representative writers such as Tran Quang Long, Dong Trinh, Tran Vang Sao, Ngo Kha, Tan Hoai Da Vu, Thai Ngoc San, Le Van Ngan, etc. for research. Here, the concept of "progressive patriotism" is understood in the sense of fighting against foreign invaders, fighting for independence and freedom, expressing national pride and self-respect; distinguishing it from the urban youth poetry that is outside this "patriotic framework" (and also outside the scope of the topic; however, when necessary, comparison and contrast can be made).
Particularly in source 1 (young Northern poetry), poems that for some reason were not published during the anti-American period (or were published but on a limited scale), are now widely and publicly circulated: such as Luu Quang Vu - Posthumous Works ; poems by Ly Phuong Lien, Le Huy Quang, Hoang Hung, Le Xuan Do,... And also Pham Tien Duat (poem Unpopulated Forests ), Lam Thi My Da (poem Days Without You ), Bang Viet (poem Thinking Back About Pauxtopxky ),... Or some newly collected compositions (printed in Khuc Truong Ca Thanh Co [10]): Poems by Tran Le An, Pham Dong Hung, Nguyen Trong Dinh, Nguyen Van Thac, Nguyen Hai Nghiem,... are all within the scope of our survey.
- Regarding the materials: We exploit the poems of many generations composed during the period of fighting against the US to save the country. The main source is the poems of the young generation of poets, extending to the poems of the resistance against the French and the first period of poetry after 1975, but the quantity is not much, only used when necessary.
4. RESEARCH METHODS
Maybe you are interested!
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Qos Assurance Methods for Multimedia Communications
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low. The EF PHB requires a sufficiently large number of output ports to provide low delay, low loss, and low jitter.
EF PHBs can be implemented if the output port's bandwidth is sufficiently large, combined with small buffer sizes and other network resources dedicated to EF packets, to allow the router's service rate for EF packets on an output port to exceed the arrival rate λ of packets at that port.
This means that packets with PHB EF are considered with a pre-allocated amount of output bandwidth and a priority that ensures minimum loss, minimum delay and minimum jitter before being put into operation.
PHB EF is suitable for channel simulation, leased line simulation, and real-time services such as voice, video without compromising on high loss, delay and jitter values.
Figure 2.10 Example of EF installation
Figure 2.10 shows an example of an EF PHB implementation. This is a simple priority queue scheduling technique. At the edges of the DS domain, EF packet traffic is prioritized according to the values agreed upon by the SLA. The EF queue in the figure needs to output packets at a rate higher than the packet arrival rate λ. To provide an EF PHB over an end-to-end DS domain, bandwidth at the output ports of the core routers needs to be allocated in advance to ensure the requirement μ > λ. This can be done by a pre-configured provisioning process. In the figure, EF packets are placed in the priority queue (the upper queue). With such a length, the queue can operate with μ > λ.
Since EF was primarily used for real-time services such as voice and video, and since real-time services use UDP instead of TCP, RED is generally
not suitable for EF queues because applications using UDP will not respond to random packet drop and RED will strip unnecessary packets.
2.2.4.2 Assured Forwarding (AF) PHB
PHB AF is defined by RFC 2597. The purpose of PHB AF is to deliver packets reliably and therefore delay and jitter are considered less important than packet loss. PHB AF is suitable for non-real-time services such as applications using TCP. PHB AF first defines four classes: AF1, AF2, AF3, AF4. For each of these AF classes, packets are then classified into three subclasses with three distinct priority levels.
Table 2.8 shows the four AF classes and 12 AF subclasses and the DSCP values for the 12 AF subclasses defined by RFC 2597. RFC 2597 also allows for more than three separate priority levels to be added for internal use. However, these separate priority levels will only have internal significance.
PHB Class
PHB Subclass
Package type
DSCP
AF4
AF41
Short
100010
AF42
Medium
100100
AF43
High
100110
AF3
AF31
Short
011010
AF32
Medium
011100
AF33
High
011110
AF2
AF21
Short
010010
AF22
Medium
010100
AF23
High
010110
AF1
AF11
Short
001010
AF12
Medium
001100
AF13
High
001110
Table 2.8 AF DSCPs
The AF PHB ensures that packets are forwarded with a high probability of delivery to the destination within the bounds of the rate agreed upon in an SLA. If AF traffic at an ingress port exceeds the pre-priority rate, which is considered non-compliant or “out of profile”, the excess packets will not be delivered to the destination with the same probability as the packets belonging to the defined traffic or “in profile” packets. When there is network congestion, the out of profile packets are dropped before the in profile packets are dropped.
When service levels are defined using AF classes, different quantity and quality between AF classes can be realized by allocating different amounts of bandwidth and buffer space to the four AF classes. Unlike
EF, most AF traffic is non-real-time traffic using TCP, and the RED queue management strategy is an AQM (Adaptive Queue Management) strategy suitable for use in AF PHBs. The four AF PHB layers can be implemented as four separate queues. The output port bandwidth is divided into four AF queues. For each AF queue, packets are marked with three “colors” corresponding to three separate priority levels.
In addition to the 32 DSCP 1 groups defined in Table 2.8, 21 DSCPs have been standardized as follows: one for PHB EF, 12 for PHB AF, and 8 for CSCP. There are 11 DSCP 1 groups still available for other standards.
2.2.5.Example of Differentiated Services
We will look at an example of the Differentiated Service model and mechanism of operation. The architecture of Differentiated Service consists of two basic sets of functions:
Edge functions: include packet classification and traffic conditioning. At the inbound edge of the network, incoming packets are marked. In particular, the DS field in the packet header is set to a certain value. For example, in Figure 2.12, packets sent from H1 to H3 are marked at R1, while packets from H2 to H4 are marked at R2. The labels on the received packets identify the service class to which they belong. Different traffic classes receive different services in the core network. The RFC definition uses the term behavior aggregate rather than the term traffic class. After being marked, a packet can be forwarded immediately into the network, delayed for a period of time before being forwarded, or dropped. We will see that there are many factors that affect how a packet is marked, and whether it is forwarded immediately, delayed, or dropped.
Figure 2.12 DiffServ Example
Core functionality: When a DS-marked packet arrives at a Diffservcapable router, the packet is forwarded to the next router based on
Per-hop behavior is associated with packet classes. Per-hop behavior affects router buffers and the bandwidth shared between competing classes. An important principle of the Differentiated Service architecture is that a router's per-hop behavior is based only on the packet's marking or the class to which it belongs. Therefore, if packets sent from H1 to H3 as shown in the figure receive the same marking as packets from H2 to H4, then the network routers treat the packets exactly the same, regardless of whether the packet originated from H1 or H2. For example, R3 does not distinguish between packets from h1 and H2 when forwarding packets to R4. Therefore, the Differentiated Service architecture avoids the need to maintain router state about separate source-destination pairs, which is important for network scalability.
Chapter Conclusion
Chapter 2 has presented and clarified two main models of deploying and installing quality of service in IP networks. While the traditional best-effort model has many disadvantages, later models such as IntServ and DiffServ have partly solved the problems that best-effort could not solve. IntServ follows the direction of ensuring quality of service for each separate flow, it is built similar to the circuit switching model with the use of the RSVP resource reservation protocol. IntSer is suitable for services that require fixed bandwidth that is not shared such as VoIP services, multicast TV services. However, IntSer has disadvantages such as using a lot of network resources, low scalability and lack of flexibility. DiffServ was born with the idea of solving the disadvantages of the IntServ model.
DiffServ follows the direction of ensuring quality based on the principle of hop-by-hop behavior based on the priority of marked packets. The policy for different types of traffic is decided by the administrator and can be changed according to reality, so it is very flexible. DiffServ makes better use of network resources, avoiding idle bandwidth and processing capacity on routers. In addition, the DifServ model can be deployed on many independent domains, so the ability to expand the network becomes easy.
Chapter 3: METHODS TO ENSURE QoS FOR MULTIMEDIA COMMUNICATIONS
In packet-switched networks, different packet flows often have to share the transmission medium all the way to the destination station. To ensure the fair and efficient allocation of bandwidth to flows, appropriate serving mechanisms are required at network nodes, especially at gateways or routers, where many different data flows often pass through. The scheduler is responsible for serving packets of the selected flow and deciding which packet will be served next. Here, a flow is understood as a set of packets belonging to the same priority class, or originating from the same source, or having the same source and destination addresses, etc.
In normal state when there is no congestion, packets will be sent as soon as they are delivered. In case of congestion, if QoS assurance methods are not applied, prolonged congestion can cause packet drops, affecting service quality. In some cases, congestion is prolonged and widespread in the network, which can easily lead to the network being "frozen", or many packets being dropped, seriously affecting service quality.
Therefore, in this chapter, in sections 3.2 and 3.3, we introduce some typical network traffic load monitoring techniques to predict and prevent congestion before it occurs through the measure of dropping (removing) packets early when there are signs of impending congestion.
3.1. DropTail method
DropTail is a simple, traditional queue management method based on FIFO mechanism. All incoming packets are placed in the queue, when the queue is full, the later packets are dropped.
Due to its simplicity and ease of implementation, DropTail has been used for many years on Internet router systems. However, this algorithm has the following disadvantages:
− Cannot avoid the phenomenon of “Lock out”: Occurs when 1 or several traffic streams monopolize the queue, making packets of other connections unable to pass through the router. This phenomenon greatly affects reliable transmission protocols such as TCP. According to the anti-congestion algorithm, when locked out, the TCP connection stream will reduce the window size and reduce the packet transmission speed exponentially.
− Can cause Global Synchronization: This is the result of a severe “Lock out” phenomenon. Some neighboring routers have their queues monopolized by a number of connections, causing a series of other TCP connections to be unable to pass through and simultaneously reducing the transmission speed. After those monopolized connections are temporarily suspended,
Once the queue is cleared, it takes a considerable amount of time for TCP connections to return to their original speed.
− Full Queue phenomenon: Data transmitted on the Internet often has an explosion, packets arriving at the router are often in clusters rather than in turn. Therefore, the operating mechanism of DropTail makes the queue easily full for a long period of time, leading to the average delay time of large packets. To avoid this phenomenon, with DropTail, the only way is to increase the router's buffer, this method is very expensive and ineffective.
− No QoS guarantee: With the DropTail mechanism, there is no way to prioritize important packets to be transmitted through the router earlier when all are in the queue. Meanwhile, with multimedia communication, ensuring connection and stable speed is extremely important and the DropTail algorithm cannot satisfy.
The problem of choosing the buffer size of the routers in the network is to “absorb” short bursts of traffic without causing too much queuing delay. This is necessary in bursty data transmission. The queue size determines the size of the packet bursts (traffic spikes) that we want to be able to transmit without being dropped at the routers.
In IP-based application networks, packet dropping is an important mechanism for indirectly reporting congestion to end stations. A solution that prevents router queues from filling up while reducing the packet drop rate is called dynamic queue management.
3.2. Random elimination method – RED
3.2.1 Overview
RED (Random Early Detection of congestion; Random Early Drop) is one of the first AQM algorithms proposed in 1993 by Sally Floyd and Van Jacobson, two scientists at the Lawrence Berkeley Laboratory of the University of California, USA. Due to its outstanding advantages compared to previous queue management algorithms, RED has been widely installed and deployed on the Internet.
The most fundamental point of their work is that the most effective place to detect congestion and react to it is at the gateway or router.
Source entities (senders) can also do this by estimating end-to-end delay, throughput variability, or the rate of packet retransmissions due to drop. However, the sender and receiver view of a particular connection cannot tell which gateways on the network are congested, and cannot distinguish between propagation delay and queuing delay. Only the gateway has a true view of the state of the queue, the link share of the connections passing through it at any given time, and the quality of service requirements of the
traffic flows. The RED gateway monitors the average queue length, which detects early signs of impending congestion (average queue length exceeding a predetermined threshold) and reacts appropriately in one of two ways:
− Drop incoming packets with a certain probability, to indirectly inform the source of congestion, the source needs to reduce the transmission rate to keep the queue from filling up, maintaining the ability to absorb incoming traffic spikes.
− Mark “congestion” with a certain probability in the ECN field in the header of TCP packets to notify the source (the receiving entity will copy this bit into the acknowledgement packet).
Figure 3. 1 RED algorithm
The main goal of RED is to avoid congestion by keeping the average queue size within a sufficiently small and stable region, which also means keeping the queuing delay sufficiently small and stable. Achieving this goal also helps: avoid global synchronization, not resist bursty traffic flows (i.e. flows with low average throughput but high volatility), and maintain an upper bound on the average queue size even in the absence of cooperation from transport layer protocols.
To achieve the above goals, RED gateways must do the following:
− The first is to detect congestion early and react appropriately to keep the average queue size small enough to keep the network operating in the low latency, high throughput region, while still allowing the queue size to fluctuate within a certain range to absorb short-term fluctuations. As discussed above, the gateway is the most appropriate place to detect congestion and is also the most appropriate place to decide which specific connection to report congestion to.
− The second thing is to notify the source of congestion. This is done by marking and notifying the source to reduce traffic. Normally the RED gateway will randomly drop packets. However, if congestion
If congestion is detected before the queue is full, it should be combined with packet marking to signal congestion. The RED gateway has two options: drop or mark; where marking is done by marking the ECN field of the packet with a certain probability, to signal the source to reduce the traffic entering the network.
− An important goal that RED gateways need to achieve is to avoid global synchronization and not to resist traffic flows that have a sudden characteristic. Global synchronization occurs when all connections simultaneously reduce their transmission window size, leading to a severe drop in throughput at the same time. On the other hand, Drop Tail or Random Drop strategies are very sensitive to sudden flows; that is, the gateway queue will often overflow when packets from these flows arrive. To avoid these two phenomena, gateways can use special algorithms to detect congestion and decide which connections will be notified of congestion at the gateway. The RED gateway randomly selects incoming packets to mark; with this method, the probability of marking a packet from a particular connection is proportional to the connection's shared bandwidth at the gateway.
− Another goal is to control the average queue size even without cooperation from the source entities. This can be done by dropping packets when the average size exceeds an upper threshold (instead of marking it). This approach is necessary in cases where most connections have transmission times that are less than the round-trip time, or where the source entities are not able to reduce traffic in response to marking or dropping packets (such as UDP flows).
3.2.2 Algorithm
This section describes the algorithm for RED gateways. RED gateways calculate the average queue size using a low-pass filter. This average queue size is compared with two thresholds: minth and maxth. When the average queue size is less than the lower threshold, no incoming packets are marked or dropped; when the average queue size is greater than the upper threshold, all incoming packets are dropped. When the average queue size is between minth and maxth, each incoming packet is marked or dropped with a probability pa, where pa is a function of the average queue size avg; the probability of marking or dropping a packet for a particular connection is proportional to the bandwidth share of that connection at the gateway. The general algorithm for a RED gateway is described as follows: [5]
For each packet arrival
Caculate the average queue size avg If minth ≤ avg < maxth
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Young Vietnamese Poetry During the Anti-American Resistance War - Inspiration and Tone - 1 -
Pre-tax Profit of Bidv Tien Giang in the Period 2011-2015
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At that time, the Branch had to set aside a provision for credit risks, which reduced the Branch's income.
Chart 2.2. Pre-tax profit of BIDV Tien Giang in the period 2011-2015
Unit: Billion VND
140
120
100
80
60
40
20
0
63.3
80.34
89.29
110.08
131.99
2011 2012 2013 2014 2015
Profit before tax
(Source: Report on the implementation of the annual business plan of the General Planning Department of BIDV Tien Giang [24])
However, through chart 2.2, it can be seen that BIDV Tien Giang's profit is still increasing continuously, and its operating efficiency is currently leaking. This is a contribution of non-credit services, and this service segment will be increasingly focused on growth by BIDV Tien Giang to ensure the highest profit safety because credit activities have many potential risks. At the same time, focusing on developing non-credit services is consistent with one of the contents of restructuring the financial activities of credit institutions in the project "Restructuring the system of credit institutions in the period 2011-2015" approved by the Prime Minister in Decision No. 254/QD-TTg dated March 1, 2012 [14]: "Gradually shifting the business model of commercial banks towards reducing dependence on credit activities and increasing income from non-credit services".
2.2. Current status of non-credit service development at BIDV Tien Giang.
2.2.1. BIDV Tien Giang has deployed the development of non-credit services in recent times.
Along with the development of the Head Office, BIDV Tien Giang's products and services are constantly improved and deployed in a diverse manner to ensure provision for many different customer groups in the area: individual customers, corporate customers, and financial institutions. Typical services are as follows: Payment services, treasury services, guarantee services, card services, trade finance, other services: Western Union, insurance commissions, consulting services, foreign exchange derivatives trading, e-banking services,...
2.2.1.1. Payment services:
In accordance with the Prime Minister's Project to promote non-cash payments in Vietnam [15], banks in Tien Giang province have continuously developed payment services to reduce customers' cash usage habits through card services and electronic banking services such as: salary payment through accounts, focusing on developing card acceptance points, developing multi-purpose cards, paying social insurance by transfer, paying bills through banks, etc.
Chart 2.3. Net income from payment services in the period 2011-2015
Unit: Million VND
6000
5000
4000
3000
2000
1000
0
3922 4065
4720 5084 5324
2011 2012 2013 2014 2015
Net income from payment services
(Source: Report on the implementation of the annual business plan of the General Planning Department of BIDV Tien Giang [24])
Along with the technological development of the entire system, BIDV Tien Giang has a payment system with a fairly stable transaction processing speed, bringing many conveniences to customers. The results of observing chart 2.3 show that the income from payment services that the Branch has achieved has grown over the years but the speed is not high and the products are not outstanding compared to other banks. Domestic payment products such as: Online bill payment, electricity bills, water bills, insurance premiums, cable TV bills, telecommunications fees, airline tickets, etc. bring many conveniences to customers. Regarding international payment, this is an indispensable activity for foreign economic activities, BIDV Tien Giang is providing international payment methods for small enterprises producing agriculture, aquatic food and seafood that have credit relationships with banks in industrial parks in Tien Giang province such as: money transfer, collection, L/C payment.
2.2.1.2. Treasury services:
BIDV Tien Giang always focuses on ensuring treasury safety and currency security, always complies with legal regulations, and minimizes risks in operations such as: counting and collecting money from customers, receiving and delivering internal transactions, collecting from the State Bank (SBV) or other credit institutions, receiving ATM funds, bundling money, etc. BIDV Tien Giang's treasury service management department is always fully equipped with modern machinery and equipment such as: money transport vehicles, fire prevention tools, money counters, money detectors, magnifying glasses, etc. to ensure absolute safety in treasury operations, immediately identifying real and fake money and other risks that may affect people and assets of the bank and customers. In addition, implementing regulation 2480/QC dated October 28, 2008 between the State Bank of Tien Giang province and the Provincial Police on coordination in the fight against counterfeit money, in the 3-year review of implementation, BIDV Tien Giang discovered, seized and submitted to the State Bank of Tien Giang province 475 banknotes of various denominations and was commended by the Provincial Police and the State Bank of Tien Giang province [17].
Chart 2.4. Net income from treasury services in the period 2011-2015
Unit: Million VND
350
300
250
200
150
100
50
0
105 122
309 289 279
2011 2012 2013 2014 2015
Net income from treasury services
(Source: Report on the implementation of the annual business plan of the General Planning Department of BIDV Tien Giang [24])
However, as shown in Figure 2.4, income from treasury operations is not high and fluctuates. Specifically, in the period 2011-2013, net income increased and increased most sharply in 2013, then in the period 2013-2015, there was a downward trend. This fluctuation is due to the fact that fees collected from treasury services are often very low and can even be waived to attract customers to use other services.
2.2.1.3. Guarantee and trade finance services:
BIDV Tien Giang, thanks to the advantages of the province and the favorable location of the Branch, has continuously focused on developing income from guarantee services and trade finance.
Chart 2.5. Net income from guarantee and trade finance services in the period 2011-2015
Unit: Million VND
14000
12000
10000
8000
6000
4000
2000
0
5193 5695
2742 3420
8889
3992
11604 12206
5143 5312
2011 2012 2013 2014 2015
Net income from guarantee services Net income from Trade Finance
(Source: Report on the implementation of the annual business plan of the General Planning Department of BIDV Tien Giang [24])
Through chart 2.5, we can see that BIDV Tien Giang's income from guarantee services and trade finance has grown over the years. The reason is: Among BIDV Tien Giang's corporate customers, the construction industry is the industry with the highest proportion of customers after the trading industry, this is a group of customers with potential to develop guarantee services. The second group of customers is corporate customers in the fields of agricultural production, livestock and seafood processing with high import and export turnover in the area.
are the target of trade finance development. In addition, BIDV Tien Giang also focuses on continuously developing these customer groups to increase revenue for many other products and services in the future.
2.2.1.4. Card and POS services:
As a service that BIDV Tien Giang has recently developed strongly, it can be said that this is a very potential market and has the ability to develop even more strongly in the future. Card services with outstanding advantages such as fast payment time, wide payment range, quite safe, effective and suitable for the integration trend and the Project to promote non-cash payments in Vietnam. Cards have become a modern and popular payment tool. BIDV Tien Giang early identified that developing card services is to expand the market to people in society, create capital mobilized from card-opened accounts, contribute to diversifying banking activities, enhance the image of the bank, bring the BIDV Tien Giang brand to people as quickly and easily as possible. BIDV Tien Giang is currently providing card types such as: credit cards (BIDV MasterCard Platinum, BIDV Visa Gold Precious, BIDV Visa Manchester United, BIDV Visa Classic), international debit cards (BIDV Ready Card, BIDV Manu Debit Card), domestic debit cards (BIDV Harmony Card, BIDV eTrans Card, BIDV Moving Card, BIDV-Lingo Co-branded Card, BIDV-Co.opmart Co-branded Card). These cards can be paid via POS/EDC or on the ATM system. In addition, with debit cards, customers can not only withdraw money via ATMs but also perform utilities such as mobile top-up, online payment, money transfer,... through electronic banking services.
In order to attract customers with card services, BIDV Tien Giang has continuously increased the installation of ATMs. As of December 31, 2015, BIDV Tien Giang has 23 ATMs combined with 7 ATMs in the same system of BIDV My Tho, so the number of ATMs is quite large, especially in the center of My Tho City, but is not yet fully present in the districts. Basic services on ATMs such as withdrawing money, checking balances, printing short statements,... BIDV ATMs accept cards from banks in the system.
Banknetvn and Smartlink, cards branded by international card organizations Union Pay (CUP), VISA, MasterCard and cards of banks in the Asian Payment Network. From here, cardholders can make bill payments for themselves or others at ATMs, by simply entering the subscriber number or customer code, booking code that service providers notify and make bill payments.
Chart 2.6. Net income from card services in the period 2011-2015
Unit: Million VND
3500
3000
2500
2000
1500
1000
500
0
687
1023
1547
2267
3104
2011 2012 2013 2014 2015
Net income from card services
(Source: Report on the implementation of the annual business plan of the General Planning Department of BIDV Tien Giang [24])
Through chart 2.6, it can be seen that BIDV Tien Giang's card service income is constantly growing because the Branch focuses on developing businesses operating in industrial parks, which are the source of customers for salary payment products, ATMs, BSMS. Specifically, there are companies such as Freeview, Quang Viet, Dai Thanh, which are businesses with a large number of card openings at the Branch, contributing to the increase in card service fees [25].
Table 2.6. Number of ATMs and POS machines in 2015 of some banks in Tien Giang area.
Unit: Machine
STT
Bank name
Number of ATMs
Cumulative number of ATM cards
POS machine
1
BIDV Tien Giang
23
97,095
22
2
BIDV My Tho
7
21,325
0
3
Agribank Tien Giang
29
115,743
77
4
Vietinbank Tien Giang
16
100,052
54
5
Dong A Tien Giang
26
97,536
11
6
Sacombank Tien Giang
24
88,513
27
7
Vietcombank Tien Giang
15
61,607
96
8
Vietinbank - Tay Tien Giang Branch
6
46,042
38
(Source: 2015 Banking Activity Data Report of the General and Internal Control Department of the Provincial State Bank [21])
Through table 2.6, the author finds that the number of ATMs of BIDV Tien Giang is not much, ranking fourth after Agribank Tien Giang, Dong A Tien Giang, Sacombank Tien Giang. The number of POS machines of BIDV Tien Giang is very small, only higher than Dong A Tien Giang and BIDV My Tho in the initial stages of merging the BIDV system. Besides, BIDV Tien Giang has a high number of cards increasing over the years (table 2.7) but the cumulative number of cards issued up to December 31, 2015 is still relatively low compared to Agribank, Vietcombank, Dong A (table 2.6).
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Epic poem about the anti-American period in modern Vietnamese literature - Nguyen Thi Lien Tam - 9 -
Improving the competitiveness of Vietnamese hotels in the coming time - 14
4.1. Historical method
In studying the inspiration and tone of young poetry during the anti-American period, we put all the works of this generation of poets into a specific historical context (the war of national liberation) for examination; research in a dialectical relationship in an objective, scientific order. At the same time, the inspiration and tone of young poetry are also examined in a close relationship with anti-American poetry in particular, and the process of resistance poetry in general.

4.2. Systemic method
Every element exists in a system, and any system contains its constituent elements. We consider the inspiration and tone in young poetry during the anti-American period as a system. Studying this system means going into the survey and analysis.
forms of inspiration and types of tone (i.e. elements). The relationship between the elements of inspiration and the elements of tone is the dialectical relationship between thought and art, content and form.
4.3. Comparison and contrast method
From the results of the systematic method, we compare and contrast the inspiration and tone in young poetry during the anti-American period with the inspiration and tone in the anti-American poetry of previous generations to clarify the characteristics of young poetry during the anti-American period as an artistic phenomenon, an aesthetic entity. At the same time, when necessary, we also compare on the following levels: period (patriotic poetry before and during the anti-American period); region (young anti-American poetry in the North - young anti-American poetry in the South); gender (young anti-American poetry of men - young anti-American poetry of women),...
4.4. Typological method
Researching the inspiration and tone of young poetry during the anti-American period, that is, its subject belongs to the lyrical genre. Closely following the characteristics of the genre, in the process of examining and analyzing each type of inspiration and each type of tone, we always pay attention to issues such as "lyrical ego", "lyrical character", "aesthetic emotion", "artistic symbol", "poetic form", "poetic rhythm", "inner world",...
4.5. Analysis and synthesis methods
To make the thesis convincing, we apply this method to analyze artistic signals, language structures, etc.; thereby synthesizing and highlighting the forms of inspiration and types of tones in Vietnamese youth poetry during the anti-American period.
- In addition to combining the above methods, to examine images and colors with symbolic meaning; to examine the organization of artistic text,... we also use the method of poetics .
5. CONTRIBUTIONS OF THE THESIS
● About theory:
Contribute to concretizing inspiration and artistic tone (through a survey of young poetry during the anti-American period); apply to the study of a poetic genre that arose in a special historical period.
● Regarding literary history: - Clarifying the scope of anti-American poetry; the concept of "young poetry", the milestones of formation and stages of movement of young poetry during the anti-American period. This is an issue that currently has different opinions.
- Discuss and prove the forms of inspiration and types of tone in young poetry during the anti-American period; affirm the contributions of this poetic genre to the cause of national liberation and the development of modern Vietnamese poetry; point out some of its limitations.
● In practice: Contribute to the teaching and learning of anti-American poetry in general and young poetry in particular in a new direction, suitable for the country's integration period.
6. THESIS STRUCTURE
In addition to the Introduction (30 pages), Conclusion (5 pages), References (199 topics), and Poems surveyed (109 topics); the structure of the Thesis includes:
- Chapter 1. Anti-American poetry and Vietnamese youth poetry during the anti-American resistance war (43 pages): Overview, generalization of anti-American poetry and Vietnamese youth poetry during the anti-American resistance war; solving problems of time span, characteristics (anti-American poetry), concepts, processes (youth poetry during the anti-American resistance war).
- Chapter 2. Artistic inspiration in young Vietnamese poetry during the anti-American resistance war (58 pages): Presents the theoretical concept of inspiration; analyzes the forms of inspiration (romantic - epic, committed - involved, tragic, personal and worldly) and some methods of expressing inspiration.
- Chapter 3. The tone of Vietnamese young poetry during the anti-American resistance war (56 pages): Presents the theoretical concept of tone; analyzes the types of tone (optimistic generosity, lyrical sadness, philosophical contemplation, tormented self-questioning) and some techniques for creating tone.
CHAPTER 1
ANTI-AMERICAN POETRY AND VIETNAMESE YOUTH POETRY DURING THE ANTI-AMERICAN RESISTANCE WAR
1.1. Anti-American poetry: Time range, outstanding features
1.1.1. Time amplitude
The name “Anti-American Poetry” has been used since the war had not yet stopped. However, not everyone and not at all times agrees on its time range.
We believe that the amplitude of the resistance war against the US, as defined by historical compilers, is consistent with the idea that “Vietnam is one, the Vietnamese people are one” (Ho Chi Minh). To be more specific, it means that since the US sent troops to the South (1955) under the guise of “advisers” to build a political regime, against the Vietnamese people’s desire for national unification, the US officially invaded Vietnam. At the same time, the struggle of the people in the South in many forms, in all fields (including poetry) was considered an anti-US attitude and action (regardless of North and South). When bombs and bullets spread throughout the country, the US imperialists crazily attacked the North, and massively sent troops to the South (1965), the situation of the war had entered an extremely fierce phase (escalation of the war), not that the resistance war against the US had just begun from here. The truth is obvious, everyone understands it like that.
However, in terms of literature, some documents determine that the range of anti-American poetry began from 1964 (or 1965) to 1975, that is, in about ten years. The book "History of Vietnamese Literature" volume III wrote: "The resistance war against the US to save the country to liberate the South and protect the North lasted more than 10 years..." [94, p.120]. Not only the above book History of Literature, but previously, most literary historians divided Vietnamese poetry in the period 1955 - 1975 into two stages. The first stage was from 1955 to 1964, the second stage was from 1965 to 1975. In fact, literary historians based their analysis on the two strategic tasks of the Vietnamese revolution after the resistance war.
Victory against the French (1954): the North restored the economy and built socialism, the South fought to unify the country (political criteria).
However, in literature, it is difficult to have such a clear cut. Moreover, the name “Poetry of the struggle for national unification” (only one of the two contents in the poetry of 1955 - 1964) with the concept of “anti-American poetry”, in our opinion, is only one. And it is even more impossible to wait until the American invaders massively wage war throughout the country before there is anti-American poetry. Regarding this issue, researcher Nguyen Dang Diep, in the article “Anti-American poetry, achievements and artistic experiences” has a passage: “Up to now, when researching anti-American poetry, many people believe that anti-American poetry falls within the period from 1965 to 1975. However, it is necessary to pay more attention to the amplitude: In fact, anti-American poetry appeared quite a lot right after the Geneva Agreement was signed. Furthermore, although this war ended in 1975, in the late 70s and early 80s of the 20th century, many excellent poems and epic poems appeared praising the great national war of defense" [29, p.11].
According to Nguyen Dang Diep, the expansion of anti-American poetry should be more than ten years before 1965 and should be extended after the war ended (1975) by about ten years. That is, in fact, in the first decade of the post-war period, by inertia, epic inspiration was still dominant, although the expression tendency was somewhat different from the wartime. That is not to mention, in the late 1970s, when the Southwestern border war and the Northern border war broke out, poetry continued to go to war, the spirit of the anti-American poetry period echoed again, the heroic voice re-emerged: "The North floods, the South floods, blood soaks the border / Hands against the sky, hands to protect the country, straining the tendons" (To Huu). However, in our opinion, about ten years after the liberation of the South, poets who wrote about the fierce resistance war that they had experienced (Huu Thinh, Thanh Thao, Nguyen Duc Mau, Tran Manh Hao, ...) should be considered as poems about the theme of war, writing about a time to remember, rather than anti-American poems as they composed during the war years. Therefore, it is impossible to separate anti-American poetry from the anti-American resistance war. In our opinion, the amplitude of anti-American poetry coincides with the resistance war that our people waged continuously for more than twenty years (1955 - 1975). The ten years (1965 - 1975) are considered as
The peak of anti-American poetry, or as Nguyen Hoang Son said, was the birth of the " Anti-American Poetry Movement" [133, p.21].
Regarding this issue, researcher Nguyen Ba Thanh affirmed: “Anti-American poetry began with poetry fighting for national reunification, but it really flourished when the war broke out nationwide” [160, p.245]. Similarly, researcher Vu Tuan Anh wrote: “Anti-American poetry was like a river that gushed forth from 1964, but there were preconditions…. Anti-American poetry had been heard in the South since 1955, 1956, when American military advisors strode swaggeringly on the streets of Saigon, when their plot to permanently divide our country and turn it into a new type of colony was exposed” [3, p.116] .
If we consider the time range like that, then all the works before 1965 with content expressing the desire for national reunification, condemning the crimes of the US - Diem, praising the heroic fighting spirit of the people of the South, such as " Vietnamese daughter", "Forever and ever hatred, never vanish", "Can there be peace" by To Huu, "His grave flowers bloom" by Thanh Hai, "Homeland" by Giang Nam, "The song of the wandering birds" by Thu Bon, "Remembering the river of the homeland" , "Sound of waves" by Te Hanh, "The sound of roosters crowing", "Heroic rivers" by Ca Le Hien, Bright fire in the forest by Thai Giang, ... are all in the flow of anti-American poetry to save the country.
Another issue arising from research works is that there are currently different opinions about the starting point of the Anti-American Poetry Movement , that is, poetry during the war years that spread throughout the country (1965 - 1975). In "Vietnamese Literature Against America to Save the Country", there is a passage: "Anti-American poetry from 1964 was a climax with new developments in both quantity and quality" [195, p.117]. Or, according to the compilers of "History of Vietnamese Literature, Volume III", " 1964 - 1975. Literature during the climax of the anti-American resistance to save the country" [94, p.52]. However, in "Textbook of Modern Vietnamese Literature, Volume II", it is determined: "Poetry during the period of resistance against America ( 1965 - 1975)" [79, p.39]. In 2005, in his article, researcher Nguyen Dang Diep confirmed: "Up to now, when researching anti-American poetry, many people believe that anti-American poetry is from 1965 to 1975" [29, p.11].
So, which year should be taken as the starting point for the anti-American poetry movement? 1964 or 1965? Taking 1964 as the starting point also has its basis. That is, after the Gulf of Tonkin incident, the bombs and bullets of the US imperialists officially crossed the 17th parallel, challenging the survival of the nation, the North surged with fighting spirit; anti-American poetry was strongly promoted, showing "more intense" and more urgent than before. However, in our opinion, the amplitude of the second stage must start from 1965 to the end of the war in 1975. That is, from the time the US soldiers entered the battlefield, directly confronting our army and people, and simultaneously massively attacking the North; when the anti-American spirit was pushed to its peak, especially after President Ho Chi Minh's Appeal . And when poetry all over the country was filled with epic inspiration, marching to battle; From then on, anti-American poetry rose like a movement whose echoes went beyond borders.
In addition, in Nguyen Trong Tao's opinion, the range of anti-American poetry began in 1960 and ended in 1975. In the article "Youthful qualities in young anti-American poetry" there is a passage: "The soul music of anti-American poetry ( 1960 - 1975) is the optimistic marching music full of vitality of a nation that dared to "cut through Truong Son to save the country" [149, p.117]. Because this is not a research article in the form of literary history, Nguyen Trong Tao does not explain why 1960 was taken as the starting point for anti-American poetry. We speculate that the author of the article may have based on the turning point of the anti-American resistance that took place in 1960: the Dong Khoi Ben Tre Movement, the birth of the Southern Liberation Front, and the following year the Southern Liberation Literature and Arts Association was established. These events impacted poetry, pushing poetry into a more intense and fierce anti-American phase, not only in the South but Northern poetry also participated in fighting the US: "During the years of socialist peace in the North, our poets still participated in fighting the enemy on topics about the Southern battlefield" [193, p.482].
However, that is just our judgment. However, for literary historians, Nguyen Trong Tao’s above opinion can be considered a strange hypothesis, to be further thought about. We believe that if we take 1960 as the starting point of the young poetry movement during the anti-American period, it is completely reasonable (the issue will be discussed in the subsection “The movement of young poetry”).
Thus, the range of anti-American poetry (full name “Vietnamese Poetry during the Anti-American Resistance War”) includes time, space and ideological tendencies. We believe that, during the anti-American resistance war to save the country (1955 - 1975), regardless of the North or the South, the liberated zone or the zone controlled by the Saigon government, all works on the theme of patriotism, resistance to foreign invasion, demanding independence, national unity, freedom and democracy for the people are all within the common “outline” of anti-American poetry (the core of which is revolutionary poetry). That poetry has its peak as a movement: the Anti-American Poetry Movement 1965 - 1975 .
1.1.2. Outstanding features
1.1.2.1. Some characteristics of ideology and emotion
Obviously, no one wants to fight America, oppose America if America does not invade Vietnam; even more so, no one wants to launch a war with an imperialist superpower to write poetry and be proud. But the unwanted thing still happens. In fact, in this country, an anti-American poetry has appeared. That poetry has shown abundant vitality, has a shining position in the history of national poetry, and resonates beyond the borders.
Compared to the previous wars of our ancestors, this resistance war is a historical confrontation of human scale, the enemy is the most powerful and brutal empire in the world. To defeat such an enemy, it can be said that the Vietnamese people have mobilized the total strength of tradition and the times. The most prominent is still spiritual strength, ideological strength. This strength is the source of all strength, combined with material potential to create victory.
Anti-American poetry undertakes the task of propagating ideology and sentiment, transforming political sentiment into artistic sentiment. Or more correctly, political sentiment blends with artistic sentiment, a completely voluntary and natural harmony. Anti-American poetry is generally political poetry, but politics has been artisticized and poeticized: “Oh, today my heart is like a gun barrel / Destroying America is the nobility of love” (Che Lan Vien). When both politics and art are directed towards the survival of the nation, towards the independence and unity of the Fatherland; when art is powerful enough to move people’s hearts, then as Song Hong said: “Political poetry is also 100% poetry like other poems” [82, p.124]. Entering the resistance war against America, the Party and President Ho Chi Minh

![Qos Assurance Methods for Multimedia Communications
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low. The EF PHB requires a sufficiently large number of output ports to provide low delay, low loss, and low jitter.
EF PHBs can be implemented if the output ports bandwidth is sufficiently large, combined with small buffer sizes and other network resources dedicated to EF packets, to allow the routers service rate for EF packets on an output port to exceed the arrival rate λ of packets at that port.
This means that packets with PHB EF are considered with a pre-allocated amount of output bandwidth and a priority that ensures minimum loss, minimum delay and minimum jitter before being put into operation.
PHB EF is suitable for channel simulation, leased line simulation, and real-time services such as voice, video without compromising on high loss, delay and jitter values.
Figure 2.10 Example of EF installation
Figure 2.10 shows an example of an EF PHB implementation. This is a simple priority queue scheduling technique. At the edges of the DS domain, EF packet traffic is prioritized according to the values agreed upon by the SLA. The EF queue in the figure needs to output packets at a rate higher than the packet arrival rate λ. To provide an EF PHB over an end-to-end DS domain, bandwidth at the output ports of the core routers needs to be allocated in advance to ensure the requirement μ > λ. This can be done by a pre-configured provisioning process. In the figure, EF packets are placed in the priority queue (the upper queue). With such a length, the queue can operate with μ > λ.
Since EF was primarily used for real-time services such as voice and video, and since real-time services use UDP instead of TCP, RED is generally
not suitable for EF queues because applications using UDP will not respond to random packet drop and RED will strip unnecessary packets.
2.2.4.2 Assured Forwarding (AF) PHB
PHB AF is defined by RFC 2597. The purpose of PHB AF is to deliver packets reliably and therefore delay and jitter are considered less important than packet loss. PHB AF is suitable for non-real-time services such as applications using TCP. PHB AF first defines four classes: AF1, AF2, AF3, AF4. For each of these AF classes, packets are then classified into three subclasses with three distinct priority levels.
Table 2.8 shows the four AF classes and 12 AF subclasses and the DSCP values for the 12 AF subclasses defined by RFC 2597. RFC 2597 also allows for more than three separate priority levels to be added for internal use. However, these separate priority levels will only have internal significance.
PHB Class
PHB Subclass
Package type
DSCP
AF4
AF41
Short
100010
AF42
Medium
100100
AF43
High
100110
AF3
AF31
Short
011010
AF32
Medium
011100
AF33
High
011110
AF2
AF21
Short
010010
AF22
Medium
010100
AF23
High
010110
AF1
AF11
Short
001010
AF12
Medium
001100
AF13
High
001110
Table 2.8 AF DSCPs
The AF PHB ensures that packets are forwarded with a high probability of delivery to the destination within the bounds of the rate agreed upon in an SLA. If AF traffic at an ingress port exceeds the pre-priority rate, which is considered non-compliant or “out of profile”, the excess packets will not be delivered to the destination with the same probability as the packets belonging to the defined traffic or “in profile” packets. When there is network congestion, the out of profile packets are dropped before the in profile packets are dropped.
When service levels are defined using AF classes, different quantity and quality between AF classes can be realized by allocating different amounts of bandwidth and buffer space to the four AF classes. Unlike
EF, most AF traffic is non-real-time traffic using TCP, and the RED queue management strategy is an AQM (Adaptive Queue Management) strategy suitable for use in AF PHBs. The four AF PHB layers can be implemented as four separate queues. The output port bandwidth is divided into four AF queues. For each AF queue, packets are marked with three “colors” corresponding to three separate priority levels.
In addition to the 32 DSCP 1 groups defined in Table 2.8, 21 DSCPs have been standardized as follows: one for PHB EF, 12 for PHB AF, and 8 for CSCP. There are 11 DSCP 1 groups still available for other standards.
2.2.5.Example of Differentiated Services
We will look at an example of the Differentiated Service model and mechanism of operation. The architecture of Differentiated Service consists of two basic sets of functions:
Edge functions: include packet classification and traffic conditioning. At the inbound edge of the network, incoming packets are marked. In particular, the DS field in the packet header is set to a certain value. For example, in Figure 2.12, packets sent from H1 to H3 are marked at R1, while packets from H2 to H4 are marked at R2. The labels on the received packets identify the service class to which they belong. Different traffic classes receive different services in the core network. The RFC definition uses the term behavior aggregate rather than the term traffic class. After being marked, a packet can be forwarded immediately into the network, delayed for a period of time before being forwarded, or dropped. We will see that there are many factors that affect how a packet is marked, and whether it is forwarded immediately, delayed, or dropped.
Figure 2.12 DiffServ Example
Core functionality: When a DS-marked packet arrives at a Diffservcapable router, the packet is forwarded to the next router based on
Per-hop behavior is associated with packet classes. Per-hop behavior affects router buffers and the bandwidth shared between competing classes. An important principle of the Differentiated Service architecture is that a routers per-hop behavior is based only on the packets marking or the class to which it belongs. Therefore, if packets sent from H1 to H3 as shown in the figure receive the same marking as packets from H2 to H4, then the network routers treat the packets exactly the same, regardless of whether the packet originated from H1 or H2. For example, R3 does not distinguish between packets from h1 and H2 when forwarding packets to R4. Therefore, the Differentiated Service architecture avoids the need to maintain router state about separate source-destination pairs, which is important for network scalability.
Chapter Conclusion
Chapter 2 has presented and clarified two main models of deploying and installing quality of service in IP networks. While the traditional best-effort model has many disadvantages, later models such as IntServ and DiffServ have partly solved the problems that best-effort could not solve. IntServ follows the direction of ensuring quality of service for each separate flow, it is built similar to the circuit switching model with the use of the RSVP resource reservation protocol. IntSer is suitable for services that require fixed bandwidth that is not shared such as VoIP services, multicast TV services. However, IntSer has disadvantages such as using a lot of network resources, low scalability and lack of flexibility. DiffServ was born with the idea of solving the disadvantages of the IntServ model.
DiffServ follows the direction of ensuring quality based on the principle of hop-by-hop behavior based on the priority of marked packets. The policy for different types of traffic is decided by the administrator and can be changed according to reality, so it is very flexible. DiffServ makes better use of network resources, avoiding idle bandwidth and processing capacity on routers. In addition, the DifServ model can be deployed on many independent domains, so the ability to expand the network becomes easy.
Chapter 3: METHODS TO ENSURE QoS FOR MULTIMEDIA COMMUNICATIONS
In packet-switched networks, different packet flows often have to share the transmission medium all the way to the destination station. To ensure the fair and efficient allocation of bandwidth to flows, appropriate serving mechanisms are required at network nodes, especially at gateways or routers, where many different data flows often pass through. The scheduler is responsible for serving packets of the selected flow and deciding which packet will be served next. Here, a flow is understood as a set of packets belonging to the same priority class, or originating from the same source, or having the same source and destination addresses, etc.
In normal state when there is no congestion, packets will be sent as soon as they are delivered. In case of congestion, if QoS assurance methods are not applied, prolonged congestion can cause packet drops, affecting service quality. In some cases, congestion is prolonged and widespread in the network, which can easily lead to the network being frozen, or many packets being dropped, seriously affecting service quality.
Therefore, in this chapter, in sections 3.2 and 3.3, we introduce some typical network traffic load monitoring techniques to predict and prevent congestion before it occurs through the measure of dropping (removing) packets early when there are signs of impending congestion.
3.1. DropTail method
DropTail is a simple, traditional queue management method based on FIFO mechanism. All incoming packets are placed in the queue, when the queue is full, the later packets are dropped.
Due to its simplicity and ease of implementation, DropTail has been used for many years on Internet router systems. However, this algorithm has the following disadvantages:
− Cannot avoid the phenomenon of “Lock out”: Occurs when 1 or several traffic streams monopolize the queue, making packets of other connections unable to pass through the router. This phenomenon greatly affects reliable transmission protocols such as TCP. According to the anti-congestion algorithm, when locked out, the TCP connection stream will reduce the window size and reduce the packet transmission speed exponentially.
− Can cause Global Synchronization: This is the result of a severe “Lock out” phenomenon. Some neighboring routers have their queues monopolized by a number of connections, causing a series of other TCP connections to be unable to pass through and simultaneously reducing the transmission speed. After those monopolized connections are temporarily suspended,
Once the queue is cleared, it takes a considerable amount of time for TCP connections to return to their original speed.
− Full Queue phenomenon: Data transmitted on the Internet often has an explosion, packets arriving at the router are often in clusters rather than in turn. Therefore, the operating mechanism of DropTail makes the queue easily full for a long period of time, leading to the average delay time of large packets. To avoid this phenomenon, with DropTail, the only way is to increase the routers buffer, this method is very expensive and ineffective.
− No QoS guarantee: With the DropTail mechanism, there is no way to prioritize important packets to be transmitted through the router earlier when all are in the queue. Meanwhile, with multimedia communication, ensuring connection and stable speed is extremely important and the DropTail algorithm cannot satisfy.
The problem of choosing the buffer size of the routers in the network is to “absorb” short bursts of traffic without causing too much queuing delay. This is necessary in bursty data transmission. The queue size determines the size of the packet bursts (traffic spikes) that we want to be able to transmit without being dropped at the routers.
In IP-based application networks, packet dropping is an important mechanism for indirectly reporting congestion to end stations. A solution that prevents router queues from filling up while reducing the packet drop rate is called dynamic queue management.
3.2. Random elimination method – RED
3.2.1 Overview
RED (Random Early Detection of congestion; Random Early Drop) is one of the first AQM algorithms proposed in 1993 by Sally Floyd and Van Jacobson, two scientists at the Lawrence Berkeley Laboratory of the University of California, USA. Due to its outstanding advantages compared to previous queue management algorithms, RED has been widely installed and deployed on the Internet.
The most fundamental point of their work is that the most effective place to detect congestion and react to it is at the gateway or router.
Source entities (senders) can also do this by estimating end-to-end delay, throughput variability, or the rate of packet retransmissions due to drop. However, the sender and receiver view of a particular connection cannot tell which gateways on the network are congested, and cannot distinguish between propagation delay and queuing delay. Only the gateway has a true view of the state of the queue, the link share of the connections passing through it at any given time, and the quality of service requirements of the
traffic flows. The RED gateway monitors the average queue length, which detects early signs of impending congestion (average queue length exceeding a predetermined threshold) and reacts appropriately in one of two ways:
− Drop incoming packets with a certain probability, to indirectly inform the source of congestion, the source needs to reduce the transmission rate to keep the queue from filling up, maintaining the ability to absorb incoming traffic spikes.
− Mark “congestion” with a certain probability in the ECN field in the header of TCP packets to notify the source (the receiving entity will copy this bit into the acknowledgement packet).
Figure 3. 1 RED algorithm
The main goal of RED is to avoid congestion by keeping the average queue size within a sufficiently small and stable region, which also means keeping the queuing delay sufficiently small and stable. Achieving this goal also helps: avoid global synchronization, not resist bursty traffic flows (i.e. flows with low average throughput but high volatility), and maintain an upper bound on the average queue size even in the absence of cooperation from transport layer protocols.
To achieve the above goals, RED gateways must do the following:
− The first is to detect congestion early and react appropriately to keep the average queue size small enough to keep the network operating in the low latency, high throughput region, while still allowing the queue size to fluctuate within a certain range to absorb short-term fluctuations. As discussed above, the gateway is the most appropriate place to detect congestion and is also the most appropriate place to decide which specific connection to report congestion to.
− The second thing is to notify the source of congestion. This is done by marking and notifying the source to reduce traffic. Normally the RED gateway will randomly drop packets. However, if congestion
If congestion is detected before the queue is full, it should be combined with packet marking to signal congestion. The RED gateway has two options: drop or mark; where marking is done by marking the ECN field of the packet with a certain probability, to signal the source to reduce the traffic entering the network.
− An important goal that RED gateways need to achieve is to avoid global synchronization and not to resist traffic flows that have a sudden characteristic. Global synchronization occurs when all connections simultaneously reduce their transmission window size, leading to a severe drop in throughput at the same time. On the other hand, Drop Tail or Random Drop strategies are very sensitive to sudden flows; that is, the gateway queue will often overflow when packets from these flows arrive. To avoid these two phenomena, gateways can use special algorithms to detect congestion and decide which connections will be notified of congestion at the gateway. The RED gateway randomly selects incoming packets to mark; with this method, the probability of marking a packet from a particular connection is proportional to the connections shared bandwidth at the gateway.
− Another goal is to control the average queue size even without cooperation from the source entities. This can be done by dropping packets when the average size exceeds an upper threshold (instead of marking it). This approach is necessary in cases where most connections have transmission times that are less than the round-trip time, or where the source entities are not able to reduce traffic in response to marking or dropping packets (such as UDP flows).
3.2.2 Algorithm
This section describes the algorithm for RED gateways. RED gateways calculate the average queue size using a low-pass filter. This average queue size is compared with two thresholds: minth and maxth. When the average queue size is less than the lower threshold, no incoming packets are marked or dropped; when the average queue size is greater than the upper threshold, all incoming packets are dropped. When the average queue size is between minth and maxth, each incoming packet is marked or dropped with a probability pa, where pa is a function of the average queue size avg; the probability of marking or dropping a packet for a particular connection is proportional to the bandwidth share of that connection at the gateway. The general algorithm for a RED gateway is described as follows: [5]
For each packet arrival
Caculate the average queue size avg If minth ≤ avg < maxth
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![Pre-tax Profit of Bidv Tien Giang in the Period 2011-2015
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At that time, the Branch had to set aside a provision for credit risks, which reduced the Branchs income.
Chart 2.2. Pre-tax profit of BIDV Tien Giang in the period 2011-2015
Unit: Billion VND
140
120
100
80
60
40
20
0
63.3
80.34
89.29
110.08
131.99
2011 2012 2013 2014 2015
Profit before tax
(Source: Report on the implementation of the annual business plan of the General Planning Department of BIDV Tien Giang [24])
However, through chart 2.2, it can be seen that BIDV Tien Giangs profit is still increasing continuously, and its operating efficiency is currently leaking. This is a contribution of non-credit services, and this service segment will be increasingly focused on growth by BIDV Tien Giang to ensure the highest profit safety because credit activities have many potential risks. At the same time, focusing on developing non-credit services is consistent with one of the contents of restructuring the financial activities of credit institutions in the project Restructuring the system of credit institutions in the period 2011-2015 approved by the Prime Minister in Decision No. 254/QD-TTg dated March 1, 2012 [14]: Gradually shifting the business model of commercial banks towards reducing dependence on credit activities and increasing income from non-credit services.
2.2. Current status of non-credit service development at BIDV Tien Giang.
2.2.1. BIDV Tien Giang has deployed the development of non-credit services in recent times.
Along with the development of the Head Office, BIDV Tien Giangs products and services are constantly improved and deployed in a diverse manner to ensure provision for many different customer groups in the area: individual customers, corporate customers, and financial institutions. Typical services are as follows: Payment services, treasury services, guarantee services, card services, trade finance, other services: Western Union, insurance commissions, consulting services, foreign exchange derivatives trading, e-banking services,...
2.2.1.1. Payment services:
In accordance with the Prime Ministers Project to promote non-cash payments in Vietnam [15], banks in Tien Giang province have continuously developed payment services to reduce customers cash usage habits through card services and electronic banking services such as: salary payment through accounts, focusing on developing card acceptance points, developing multi-purpose cards, paying social insurance by transfer, paying bills through banks, etc.
Chart 2.3. Net income from payment services in the period 2011-2015
Unit: Million VND
6000
5000
4000
3000
2000
1000
0
3922 4065
4720 5084 5324
2011 2012 2013 2014 2015
Net income from payment services
(Source: Report on the implementation of the annual business plan of the General Planning Department of BIDV Tien Giang [24])
Along with the technological development of the entire system, BIDV Tien Giang has a payment system with a fairly stable transaction processing speed, bringing many conveniences to customers. The results of observing chart 2.3 show that the income from payment services that the Branch has achieved has grown over the years but the speed is not high and the products are not outstanding compared to other banks. Domestic payment products such as: Online bill payment, electricity bills, water bills, insurance premiums, cable TV bills, telecommunications fees, airline tickets, etc. bring many conveniences to customers. Regarding international payment, this is an indispensable activity for foreign economic activities, BIDV Tien Giang is providing international payment methods for small enterprises producing agriculture, aquatic food and seafood that have credit relationships with banks in industrial parks in Tien Giang province such as: money transfer, collection, L/C payment.
2.2.1.2. Treasury services:
BIDV Tien Giang always focuses on ensuring treasury safety and currency security, always complies with legal regulations, and minimizes risks in operations such as: counting and collecting money from customers, receiving and delivering internal transactions, collecting from the State Bank (SBV) or other credit institutions, receiving ATM funds, bundling money, etc. BIDV Tien Giangs treasury service management department is always fully equipped with modern machinery and equipment such as: money transport vehicles, fire prevention tools, money counters, money detectors, magnifying glasses, etc. to ensure absolute safety in treasury operations, immediately identifying real and fake money and other risks that may affect people and assets of the bank and customers. In addition, implementing regulation 2480/QC dated October 28, 2008 between the State Bank of Tien Giang province and the Provincial Police on coordination in the fight against counterfeit money, in the 3-year review of implementation, BIDV Tien Giang discovered, seized and submitted to the State Bank of Tien Giang province 475 banknotes of various denominations and was commended by the Provincial Police and the State Bank of Tien Giang province [17].
Chart 2.4. Net income from treasury services in the period 2011-2015
Unit: Million VND
350
300
250
200
150
100
50
0
105 122
309 289 279
2011 2012 2013 2014 2015
Net income from treasury services
(Source: Report on the implementation of the annual business plan of the General Planning Department of BIDV Tien Giang [24])
However, as shown in Figure 2.4, income from treasury operations is not high and fluctuates. Specifically, in the period 2011-2013, net income increased and increased most sharply in 2013, then in the period 2013-2015, there was a downward trend. This fluctuation is due to the fact that fees collected from treasury services are often very low and can even be waived to attract customers to use other services.
2.2.1.3. Guarantee and trade finance services:
BIDV Tien Giang, thanks to the advantages of the province and the favorable location of the Branch, has continuously focused on developing income from guarantee services and trade finance.
Chart 2.5. Net income from guarantee and trade finance services in the period 2011-2015
Unit: Million VND
14000
12000
10000
8000
6000
4000
2000
0
5193 5695
2742 3420
8889
3992
11604 12206
5143 5312
2011 2012 2013 2014 2015
Net income from guarantee services Net income from Trade Finance
(Source: Report on the implementation of the annual business plan of the General Planning Department of BIDV Tien Giang [24])
Through chart 2.5, we can see that BIDV Tien Giangs income from guarantee services and trade finance has grown over the years. The reason is: Among BIDV Tien Giangs corporate customers, the construction industry is the industry with the highest proportion of customers after the trading industry, this is a group of customers with potential to develop guarantee services. The second group of customers is corporate customers in the fields of agricultural production, livestock and seafood processing with high import and export turnover in the area.
are the target of trade finance development. In addition, BIDV Tien Giang also focuses on continuously developing these customer groups to increase revenue for many other products and services in the future.
2.2.1.4. Card and POS services:
As a service that BIDV Tien Giang has recently developed strongly, it can be said that this is a very potential market and has the ability to develop even more strongly in the future. Card services with outstanding advantages such as fast payment time, wide payment range, quite safe, effective and suitable for the integration trend and the Project to promote non-cash payments in Vietnam. Cards have become a modern and popular payment tool. BIDV Tien Giang early identified that developing card services is to expand the market to people in society, create capital mobilized from card-opened accounts, contribute to diversifying banking activities, enhance the image of the bank, bring the BIDV Tien Giang brand to people as quickly and easily as possible. BIDV Tien Giang is currently providing card types such as: credit cards (BIDV MasterCard Platinum, BIDV Visa Gold Precious, BIDV Visa Manchester United, BIDV Visa Classic), international debit cards (BIDV Ready Card, BIDV Manu Debit Card), domestic debit cards (BIDV Harmony Card, BIDV eTrans Card, BIDV Moving Card, BIDV-Lingo Co-branded Card, BIDV-Co.opmart Co-branded Card). These cards can be paid via POS/EDC or on the ATM system. In addition, with debit cards, customers can not only withdraw money via ATMs but also perform utilities such as mobile top-up, online payment, money transfer,... through electronic banking services.
In order to attract customers with card services, BIDV Tien Giang has continuously increased the installation of ATMs. As of December 31, 2015, BIDV Tien Giang has 23 ATMs combined with 7 ATMs in the same system of BIDV My Tho, so the number of ATMs is quite large, especially in the center of My Tho City, but is not yet fully present in the districts. Basic services on ATMs such as withdrawing money, checking balances, printing short statements,... BIDV ATMs accept cards from banks in the system.
Banknetvn and Smartlink, cards branded by international card organizations Union Pay (CUP), VISA, MasterCard and cards of banks in the Asian Payment Network. From here, cardholders can make bill payments for themselves or others at ATMs, by simply entering the subscriber number or customer code, booking code that service providers notify and make bill payments.
Chart 2.6. Net income from card services in the period 2011-2015
Unit: Million VND
3500
3000
2500
2000
1500
1000
500
0
687
1023
1547
2267
3104
2011 2012 2013 2014 2015
Net income from card services
(Source: Report on the implementation of the annual business plan of the General Planning Department of BIDV Tien Giang [24])
Through chart 2.6, it can be seen that BIDV Tien Giangs card service income is constantly growing because the Branch focuses on developing businesses operating in industrial parks, which are the source of customers for salary payment products, ATMs, BSMS. Specifically, there are companies such as Freeview, Quang Viet, Dai Thanh, which are businesses with a large number of card openings at the Branch, contributing to the increase in card service fees [25].
Table 2.6. Number of ATMs and POS machines in 2015 of some banks in Tien Giang area.
Unit: Machine
STT
Bank name
Number of ATMs
Cumulative number of ATM cards
POS machine
1
BIDV Tien Giang
23
97,095
22
2
BIDV My Tho
7
21,325
0
3
Agribank Tien Giang
29
115,743
77
4
Vietinbank Tien Giang
16
100,052
54
5
Dong A Tien Giang
26
97,536
11
6
Sacombank Tien Giang
24
88,513
27
7
Vietcombank Tien Giang
15
61,607
96
8
Vietinbank - Tay Tien Giang Branch
6
46,042
38
(Source: 2015 Banking Activity Data Report of the General and Internal Control Department of the Provincial State Bank [21])
Through table 2.6, the author finds that the number of ATMs of BIDV Tien Giang is not much, ranking fourth after Agribank Tien Giang, Dong A Tien Giang, Sacombank Tien Giang. The number of POS machines of BIDV Tien Giang is very small, only higher than Dong A Tien Giang and BIDV My Tho in the initial stages of merging the BIDV system. Besides, BIDV Tien Giang has a high number of cards increasing over the years (table 2.7) but the cumulative number of cards issued up to December 31, 2015 is still relatively low compared to Agribank, Vietcombank, Dong A (table 2.6).
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