WO2000072532A9 - Systeme et procede pour reduire le trafic de paquets dans un reseau - Google Patents

Systeme et procede pour reduire le trafic de paquets dans un reseau

Info

Publication number
WO2000072532A9
WO2000072532A9 PCT/US2000/014381 US0014381W WO0072532A9 WO 2000072532 A9 WO2000072532 A9 WO 2000072532A9 US 0014381 W US0014381 W US 0014381W WO 0072532 A9 WO0072532 A9 WO 0072532A9
Authority
WO
WIPO (PCT)
Prior art keywords
packets
packet
network
destination
combining
Prior art date
Application number
PCT/US2000/014381
Other languages
English (en)
Other versions
WO2000072532A1 (fr
Inventor
B R Badrinath
Predeep Sudame
Original Assignee
Univ Rutgers
B R Badrinath
Predeep Sudame
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Univ Rutgers, B R Badrinath, Predeep Sudame filed Critical Univ Rutgers
Priority to AU52887/00A priority Critical patent/AU5288700A/en
Publication of WO2000072532A1 publication Critical patent/WO2000072532A1/fr
Publication of WO2000072532A9 publication Critical patent/WO2000072532A9/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
    • H04L69/04—Protocols for data compression, e.g. ROHC
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/64—Hybrid switching systems
    • H04L12/6418—Hybrid transport
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
    • H04L69/30—Definitions, standards or architectural aspects of layered protocol stacks
    • H04L69/32—Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
    • H04L69/322—Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions
    • H04L69/325—Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions in the network layer [OSI layer 3], e.g. X.25
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/64—Hybrid switching systems
    • H04L12/6418—Hybrid transport
    • H04L2012/6472—Internet
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/64—Hybrid switching systems
    • H04L12/6418—Hybrid transport
    • H04L2012/6481—Speech, voice
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
    • H04L69/30—Definitions, standards or architectural aspects of layered protocol stacks
    • H04L69/32—Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
    • H04L69/322—Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions
    • H04L69/326—Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions in the transport layer [OSI layer 4]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M7/00—Arrangements for interconnection between switching centres
    • H04M7/006—Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP), including next generation networks with a packet-switched transport layer

Definitions

  • the present invention relates generally to computer networks and more specifically to reducing packets on a network.
  • Data communication in a computer network involves the exchange of data between two or more entities interconnected by communication links and subnetworks. These entities are typically software programs executing on hardware computer platforms, such as end stations and intermediate stations. Examples of an intermediate station may be a router or switch which interconnects the communication links and subnetworks to enable transmission of data between the end stations.
  • An intermediate station may be a router or switch which interconnects the communication links and subnetworks to enable transmission of data between the end stations.
  • a local area network (LAN) is an example of a subnetwork that provides relatively short distance communication among the interconnected stations; in contrast, a wide area network (WAN) enables long distance communication over links provided by public or private telecommunications facilities.
  • Communication software executing on the end stations correlates and manages data communication with other end stations.
  • the stations typically communicate by exchanging discrete packets or frames of data according to predefined protocols. Collectively, these hardware and software components comprise a communications network. Small packets (less than the default link MTU of 512 bytes) dominate Internet traffic patterns today. Wide-area Internet traffic measurements show that as many as sixty percent (60%) of the packets transmitted over the Internet backbone are less than 44 bytes. Web servers, for example, are a leading generator of small packets. All of the TCP ACKs generated by the clients have the same destination (the web server). These ACKs are just 40 bytes in size. Another example of small packet traffic is ICP
  • ICP queries Internet Cache Protocol queries generated among web proxies.
  • ICP queries are about 60 bytes in size. This domination of small packets in Internet traffic patterns is expected to get only worse with the ever increasing web traffic and with introduction of new applications such as VoIP (Voiceover-IP applications generate small audio samples, about 40 to 60 byte packets every 40 ms).
  • VoIP Voiceover-IP applications generate small audio samples, about 40 to 60 byte packets every 40 ms).
  • the network overhead cost due to queuing, processing, routing, differential treatment and delivery is the same irrespective of the size of the packet. Hence, small packets impose a relatively higher overhead on the network. Therefore, in order to improve overall network performance, there is a need to reduce the number of packets in the network.
  • Embodiments of the present invention combine small packets with the same destination into a larger packet, thereby reducing the number of packets flowing in the network.
  • Small packets dominate Internet traffic patterns today. The overhead due to queuing, processing, routing, differential treatment, and delivery is the same irrespective of the size of the packet. Hence, small packets impose a relatively higher overhead on the network.
  • the domination of small packet traffic is expected to get only worse with the ever increasing web applications and the introduction of new applications such as Voiceover IP.
  • One aspect of the invention is a computerized method of reducing packets on a network. The method comprises combining multiple packets for a destination into an aggregated packet, and separating the aggregated packet into the multiple packets at the destination.
  • Figure 1 is a block diagram of a traditional communication network.
  • Figure 2 is a block diagram of a communication network according to an example embodiment of the invention.
  • Figure 3 A is a block diagram of a traditional router.
  • Figure 3B is a block diagram of an aggregator, such as the aggregator shown in Figure 2, according to an example embodiment of the present invention.
  • Figure 4 is a block diagram of a splitter, such as the splitter shown in Figure 2, according to an example embodiment of the present invention.
  • Figure 5 is a block diagram showing how metadata is stored when two small packets are combined at a router according to an example embodiment of the invention.
  • Figure 1 is a block diagram of a traditional communication network 100.
  • the traditional communication network 100 comprises a plurality of end stations 102 and a plurality of intermediate stations 104 interconnected by communications links.
  • the intermediate links are routers 104.
  • FIG. 2 is a block diagram of a communication network 200 according to an example embodiment of the present invention.
  • the communication network 200 comprises a plurality of end stations 202 and a plurality of intermediate stations 204.
  • the intermediate stations 204 include an aggregator and a splitter which are further described below.
  • the aggregator and the splitter function to reduce the packets on the communications link between them.
  • the aggregator combines a small packets into a larger packet so that the routers see a smaller number of packets.
  • the splitter separates these packets so that the subsequent stations in the network are unaware of the packet aggregation.
  • Aggregators, as well as splitters can be placed at intermediate stations or at end stations in the network. The placement of aggregators and splitters may be varied depending on traffic patterns, level of congestion and software application needs.
  • the aggregators as well as the splitters can be the end stations in the network.
  • the aggregators and splitters are placed at ingress and egress routers in the network.
  • the placement of aggregators and splitters may be manually configured or may be dynamically assigned according to a signaling mechanism of the present invention which is further described below.
  • the aggregated packets on the communications links between the aggregator and the splitter are treated as a special class of traffic to further enhance network performance. The number of packets in the network are reduced by combining small packets multiple times at various points in the network.
  • the placement of the aggregator in the network is based on the application and is dynamically determined by the receiver of the packets.
  • a signaling mechanism of the present invention allows the receiver of the packets to place aggregators at points in the network where packets can be combined. If the aggregation at that location in the network is ineffective, the aggregators can be dynamically or manually removed and, if desired, repositioned at another point in the network. In other words, if the application ceases to need aggregation, the network can remove the aggregators without affecting the normal network routing.
  • the signalling mechanism allows the aggregation of packets to be initiated and stopped dynamically. In an alternate embodiment, the signaling mechanism can be initiated and stopped by manual configure according to a user.
  • Figure 3 A is a block diagram of a traditional router 300. As shown in
  • FIG 3A three packets 302 are received by router 300.
  • the router 300 performs a routing table 304 lookup to determine the output queue 306 for each one of the packets. All three packets 302 leave router 300 and are transmitted across a communication link.
  • Figure 3B is a block diagram of an aggregator such as the aggregator shown in Figure 2.
  • an aggregator refers to any end station or intermediate station capable of combining multiple small packets to the same destination and sending them as one packet.
  • an aggregator may be implemented as a hardware module or a software module in a router.
  • three packets 312 are received by router 310.
  • the router 310 performs a routing table 304 lookup to determine the destination of the packets 302.
  • the router 310 comprises an aggregation module 315.
  • the three packets 302 have the same destination.
  • the aggregation module 315 combines the three packets 312 into a single packet 318 referred to herein as an "aggregated packet.”
  • the aggregated packet 318 is placed in the output queue 316 for the destination and unlike the traditional router, only the single aggregated packet leaves the router 310 and is transmitted across the communication link.
  • FIG. 4 is a block diagram of a splitter 400.
  • a splitter refers to any end station or intermediate station capable of separating an aggregated packets into the original multiple packets.
  • a splitter may be implemented as a hardware module or a software module in a router.
  • an aggregated packet 402 is received by router 400.
  • the router 400 performs a routing table 404 lookup to determine the destination of the packet 402.
  • the router 400 comprises a splitter module 406.
  • the splitter module 400 separates the aggregated packet 406 into the original multiple packets 408.
  • the multiple packets 408 are placed in the output queue 410 for router 400.
  • Aggregation as well as splitting can be performed either at layer 2 (MPLS) or at layer 3 (network layer) of the protocol stack.
  • Aggregators at layer 2 require a hardware implementation.
  • aggregators and splitters are implemented using transformer tunnels. Transformer tunnels are described in more detail in Predeep Sudame and B. R. Bardinath, "Transformer tunnels: A framework for providing route-specific adaptions," in Proceedings of the USENIX Annual Technical Conference, June 1998, pp. 191-200, which is herein incorporated by reference. However, embodiments of the present invention are not limited to being implemented with transformer tunnels and alternate embodiments are contemplated.
  • the splitter can be a node other than the final destination. This way, packets belonging to multiple destinations (for example, a subnet) can be combined using a single tunnel. Aggregators may also be dynamically placed in the network so that the bottleneck links lie between the splitters and the aggregators.
  • a computerized method of reducing packets on a network comprises combining multiple packets for a destination into an aggregated packet, transmitting the single packet to the destination, and separating the aggregated packet into the multiple packets at the destination.
  • an aggregation function combines the multiple packets for a destination into an aggregated packet using a mechanism similar to TCP delayed ACKs.
  • Every small packet is delayed by a small amount of time.
  • the process of combining small packets continues until either m (a parameter to the aggregation function described below) packets have been combined, or a timeout occurs. If no other small packets arrive before the timeout, the delayed packet is sent as is.
  • This aggregation mechanism is different from IP reassembly (performed after IP fragmentation).
  • An aggregation function combines small packets, along with their IP headers, to get a larger packet. The receiver regenerates all the original packets when it receives such an aggregated packet. Thus, this mechanism can be used even for protocols that honor message boundaries (e.g., UDP).
  • FIG. 5 is a block diagram showing how metadata is stored when two small packets are combined at a router.
  • the generated larger packet has a new protocol number (77) in the IP header.
  • the original protocol therefore has to be stored as part of the metadata, along with the original destination of the packet, if it is different than the address of the splitter node.
  • the receiver of this packet handles the packet to the protocol handler for this new protocol. This handler is responsible for removing all the metadata and restoring the packets. As small packets are delayed for some time in the hope that they can be combined with other small packets, the delayed packets see increased latency.
  • the latency depends on the packet inter-arrival rate, and the timeout set by the applications. In the best case, when m packets are combined, the timeout does not come into picture, because the buffers are flushed immediately when the packets are combined.
  • An example embodiment of an aggregation function as described above is provided below. The aggregation function is provided for illustrative purposes only.
  • Timer expires: send delayed_packet; delayed_packet null; Given that there is sufficient evidence of small packet traffic in the Internet, there are a number of benefits to be obtained by packet-level aggregation.
  • Most router implementations (such as FreeBSD, Linux, and many Cisco routers) are packet limited rather than byte limited. They place a limit on the number of packets that the router can queue irrespective of the size of each packet. For reasons of efficiency, routers store packet headers (whose sizes are independent of the packet sizes) in fast memory, and the packet payload in slow memory. The fast memory being expensive decides the queue size. Every packet, irrespective of the size, consumes one slot in the queue. Combining small packets into a larger packet reduces the number of packets seen at routers, and hence helps absorb bursts (reduce losses) for a given level of congestion.
  • every packet at a router requires a routing table lookup and incurs the same performance cost irrespective of the size of the packet. Combining small packets at a router reduces the number of packets seen by all the subsequent routers. Moreover, to implement a specific per-hop behavior (as in differential services), routers have to give preferential treatment to every packet of a particular class. By combining small packets belonging to the same class, these overheads can be reduced.
  • every packet requires a link-layer header. For example, every ethernet packet has 18 bytes overhead (2 bytes for type, 6 bytes for source address, 6 bytes for destination address, 4 bytes for CRC). Moreover, an ethernet frame also has 12 bytes of frame spacing and 8 bytes of preamble.
  • packets smaller than 46 bytes have to be padded with additional bytes to make the frame size 64 bytes. Therefore, by combining two 40 bytes packets into a larger packet, 44 bytes are saved. The gains increase further if more than two packets are combined into a larger packet.
  • Packet bursting technique reduces the padding overheads by sending back-to-back frames, however, the first frame still incurs the padding overhead and two consecutive frames must have the required inter- frame spacing.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Computer Security & Cryptography (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

L'invention concerne un système et un procédé pour réduire le trafic de paquets. Les modes de réalisation de l'invention combinent de petits paquets ayant la même destination en un large paquet et réduisent ainsi le nombre de paquets s'écoulant dans un réseau. A présent, les petits paquets dominent le trafic sur Internet. La surcharge due à la mise en files d'attente, au traitement, au routage, au traitement différentiel et à la livraison n'est pas liée à la taille des paquets; par conséquent, les petits paquets provoquent une surcharge relativement plus importante du réseau. On s'attend à ce que la prédominance du trafic des petits paquets ne va que s'empirer avec l'accroissement du nombre d'applications Web et l'introduction de nouvelles applications telles que Voiceover IP.
PCT/US2000/014381 1999-05-24 2000-05-24 Systeme et procede pour reduire le trafic de paquets dans un reseau WO2000072532A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU52887/00A AU5288700A (en) 1999-05-24 2000-05-24 System and method for network packet reduction

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US13560599P 1999-05-24 1999-05-24
US60/135,605 1999-05-24

Publications (2)

Publication Number Publication Date
WO2000072532A1 WO2000072532A1 (fr) 2000-11-30
WO2000072532A9 true WO2000072532A9 (fr) 2002-04-18

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AU (1) AU5288700A (fr)
WO (1) WO2000072532A1 (fr)

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FR2859059A1 (fr) * 2003-08-20 2005-02-25 France Telecom Procede de transmission de paquets, dispositifs d'agregation et de desagregation de paquets
US7437457B1 (en) 2003-09-08 2008-10-14 Aol Llc, A Delaware Limited Liability Company Regulating concurrent logins associated with a single account
US20060047849A1 (en) * 2004-06-30 2006-03-02 Mukherjee Shubhendu S Apparatus and method for packet coalescing within interconnection network routers
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US20070019553A1 (en) * 2005-07-19 2007-01-25 Telefonaktiebolaget Lm Ericsson (Publ) Minimizing Padding for Voice Over Internet Protocol-Type Traffic Over Radio Link Control
US10467576B2 (en) 2008-03-07 2019-11-05 Software Ag Usa, Inc. Distributed software process tracking
US9195504B2 (en) 2009-09-21 2015-11-24 Siemens Product Lifecycle Management Software Inc. Transfer of data structures in sub-linear time for systems with transfer state awareness
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CN102377650B (zh) * 2010-08-12 2015-01-07 华为技术有限公司 数据发送处理方法、装置和系统
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Publication number Publication date
WO2000072532A1 (fr) 2000-11-30
AU5288700A (en) 2000-12-12

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