WO2010105527A1

WO2010105527A1 - Compressed real-time protocol optimization method and apparatus

Info

Publication number: WO2010105527A1
Application number: PCT/CN2010/070900
Authority: WO
Inventors: 郭晓阳
Original assignee: 华为技术有限公司
Priority date: 2009-03-17
Filing date: 2010-03-07
Publication date: 2010-09-23
Also published as: CN101494526A

Abstract

The present invention provides a compressed real-time protocol optimization method. The method includes: detecting the available bandwidth of a link; if the available bandwidth is less than or equal to a preset proportion, notifying an upper layer central processor, and forbidding it to respond to a context state message. Furthermore, the present invention also provides a compression end apparatus, and the apparatus includes: a detecting module used for detecting the available bandwidth of a link; a comparison module used for comparing whether the available bandwidth is less than or equal to a preset proportion; and a response module used for determining, according to the comparison result from the comparison module, whether to respond to a context state message, and when the comparison result from the comparison module is that the available bandwidth is less than or equal to the preset proportion, for notifying an upper layer central processor, so that the said upper layer central processor notifies a bottom layer network processor, and forbids the bottom layer network processor to respond to the context state message. On the narrowband link using Compressed Real-Time Protocol (CRTP), if congestion occurs, the application of the present invention can effectively ease the avalanche effect due to the congestion aggravation caused by the original protocol algorithm, the bandwidth can be used more completely and the transmission efficiency can be improved.

Description

Optimization method and device for compressing real-time protocol

The present application claims priority to Chinese Patent Application No. 200910128856. 6, entitled "Optimization Method and Apparatus for Compressing Real-Time Protocols" on March 19, 2009, the entire contents of which are incorporated herein by reference. In this application. TECHNICAL FIELD The present invention relates to an information processing method, and in particular, to an optimization method and apparatus for compressing a real-time protocol. BACKGROUND OF THE INVENTION With the Real-time Transport Protocol (RTP) becoming the official Internet standard, there is an increasing interest in using RTP to implement interoperability between different network audio and video applications. However, when using low-speed links such as 14. 4Kb/s or 28.8Kb/s, the 12-byte RTP header is too expensive for a load of only 20 bytes. To reduce the number of bytes occupied by the header, some applications typically use a custom protocol, which reduces RTP-related functionality.

May also be make by compression IP / UDP / RTP header is small, such as compressed real time protocol (CRTP, Compressed Real-time Transport Protocol) 0 shown in FIG. 1, the compressed RTP header may be directed to the end of the application (HEADER), or a combination of IP, UDP, and RTP for Link-by-Link applications. Compressing a 40-byte combo header together is more practical than compressing a 12-byte RTP header, since the result size in both cases is about 2-4 bytes. At the same time, because of the low latency and loss rate, the Link-by-Link application is compressed and performs better. CRTP compresses the IP/UDP/RTP header of most packets to 2 bytes without sending the User Datagram Protocol (UDP) checksum, and compresses to 4 when with checksum. Bytes.

CRTP is a point-to-point compression algorithm commonly used on E1 links. The CRTP algorithm can compress IP/UDP/RTP headers of 36 bytes to 6-9 bytes, greatly improving link utilization. As shown in Figure 2a, the compression side constructs a FULL HEADER message at compression start. The FULL HEADER message contains a compressed identifier (CID, Compress identification) and a complete IP/UDP/RTP header field, which is passed to the decompressed end for decompression. End construct context (CONTEXT) entry. After the decompression end establishes the CID-IP/UDP/RTP mapping relationship, the compression end subsequently sends a packet containing only the CID to save bandwidth. The decompression end recovers the IP/UDP/RTP header field according to the CID lookup table. The decompression end checks the validity and continuity of the CID at the same time. If the CID is found to be lost, it indicates that a transmission error has occurred on the line. The decompression end constructs a context state message and sends it to the compression end to request the compression end to re-request. Send a FULL HEADER message to reconstruct the CID-IP/UDP/RTP mapping entry. In the case of a normal link, this mechanism can do a good job of error retransmission.

However, as shown in Figure 2b, if the packet is found to be lost on the decompressed end, the context state message request synchronization is initiated to the compressed end. After receiving the context state packet, the compressed end sends multiple FULL HEAD packets on multiple links. The FULL HEAD message has a total of 32 bytes of IP/UDP/RTP headers than the Compress head that is usually transmitted. The occupied bandwidth is large, which will cause a new round of congestion and an avalanche effect of transmission deterioration. Reduce transmission efficiency. Summary of the invention

An object of the embodiments of the present invention is to provide an optimization method and apparatus for compressing a real-time protocol, which can avoid an avalanche effect in which transmission degradation occurs on a decompression side packet loss under network congestion.

An embodiment of the present invention provides an optimization method for compressing a real-time protocol, where the method includes: detecting an available bandwidth of a link; and notifying an upper-layer central processor, prohibiting a response context status report, if the available bandwidth is less than or equal to a preset ratio Text.

The embodiment of the present invention further provides a compression end device, the device comprising: a detection module, configured to detect a link available bandwidth; a comparison module, configured to compare whether the available bandwidth is less than or equal to a preset ratio; and a response module, And determining, according to the comparison result of the comparison module, whether to respond to the context status message, and when the comparison result of the comparison module is that the available bandwidth is less than or equal to the preset ratio, notifying the upper layer central processor, so that the upper layer The central processor notifies the underlying network processor that it is prohibited to respond to context status messages.

On the narrowband link using the CRTP compression protocol, if traffic congestion occurs, the present invention can effectively alleviate the avalanche effect caused by the original protocol algorithm, and more fully utilize the bandwidth to improve the transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in the claims In the drawing:

Figure 1 is a schematic diagram of the RTP packet format before and after compression.

Figure 2A is a schematic diagram of the operation between the compressed end and the compressed end of the CRPT under normal conditions.

2B is a schematic diagram of the operation between the compressed end and the compressed end of the CRPT under congestion transmission.

3 is a flow chart of an embodiment of an optimization method of a compressed real-time protocol in accordance with the present invention.

4 is a flow chart of another embodiment of an optimization method of a compressed real-time protocol in accordance with the present invention. Figure 5 is a block diagram showing an embodiment of a compression end device in accordance with the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clearly, the embodiments of the present invention are further described in detail below with reference to the embodiments and drawings. The illustrative embodiments of the present invention and the description thereof are intended to explain the present invention, but are not intended to limit the invention. Embodiment 1

Referring to FIG. 3, an embodiment of the present invention provides an optimization method for compressing a real-time protocol. Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The method includes the following steps performed by the compression end after traffic congestion occurs:

Step S301: Detect the available bandwidth of the link.

For example, at the predetermined time TO, the number of bytes of the link transmission message is ByteJO, and the number of bytes of the link transmission message Byte_Tl is read at the next predetermined time T1, thereby obtaining the actual bandwidth Band=(Byte_Tl-Byte_TO) / (T1- T0), the timing of detecting the available bandwidth of the link can be realized by the number of bytes sent by the link at each predetermined time;

Optionally, the foregoing step S301 can be performed periodically or periodically.

Step S302: When the available bandwidth is less than or equal to a preset ratio, the context state message is not responded.

For example, the preset ratio can be 20% of the entire bandwidth. When the available bandwidth is less than 20% of the entire bandwidth, the upper CPU can be notified to prohibit the response to the context status message.

Optionally, before the step S301, the method further includes: receiving a context state message sent by the decompressing end, where the context state message is used to instruct the compressed end to send a complete header message.

Optionally, this embodiment may further include:

And when the available bandwidth is greater than the preset ratio, responding to the context state message, and sending a FULL HEADER message to the decompressing end.

The FULL HEADER packet includes the CID and the complete IP/UDP/RTP header field. After receiving the FULL HEADER packet, the decompressor can re-establish the CID-IP/UDP/RTP mapping according to the FULL HEADER packet. relationship.

The above response context state message may be: notify the upper layer CPU, the upper layer CPU notifies the underlying network processor (NP, Network processor), and allows response to the context state message. For example, the upper CPU will The flag bit is set to allow the status of the message state message to be acknowledged, and the underlying NP is notified by this flag bit. In this embodiment, when traffic congestion occurs on a narrowband link to which the CRTP compression protocol is applied, the avalanche effect of congestion caused by the original protocol algorithm can be effectively alleviated, and the bandwidth can be fully utilized to improve transmission efficiency. Embodiment 2

Referring to FIG. 4, an embodiment of the present invention provides another method for optimizing a compressed real-time protocol. Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Step S401: Detecting the available bandwidth of the link, and the specific method is similar to step S301;

Optionally, the foregoing step S401 may be performed periodically or periodically.

Step S402: determining whether the available bandwidth is less than or equal to a preset ratio, if it is greater than the preset ratio, step S403 is performed; if it is less than or equal to the preset ratio, step S405 is performed;

For example, depending on the actual usage of the bandwidth, the preset ratio can be set to 20%;

Step S403: Responding to a context state message;

In this step, the response to the context state message may be: notify the upper layer CPU, the upper layer CPU notifies the underlying NP, and allows the response to the context state message, for example, the upper layer CPU sets the flag bit to allow the status of the response context state message, and The underlying NP is notified by this flag bit;

Step S404: Construct a FULL HEADER message to be sent to the decompressing end device, and end the process;

Step S405: Not responding to the context state message;

In this step, the non-response context state message may be: notify the upper layer CPU, the upper layer CPU notifies the underlying network processor NP, and sets a prohibition response to the context state message, for example, the upper layer CPU sets the flag bit to prohibit the response context state report. The status of the text, and the underlying NP is notified by this flag bit;

Step S406: Adjust the traffic of the packet to adapt the traffic of the packet to the available bandwidth environment. The traffic control can be implemented by slowing down the traffic source end.

Optionally, before the step S401, the method further includes: receiving a context state message sent by the decompressing end, where the context state message is used to instruct the compressed end to send a complete header message.

This embodiment can effectively alleviate the original association when traffic congestion occurs on a narrowband link to which the CRTP compression protocol is applied. At the same time, the avalanche effect caused by the congestion caused by the algorithm is further controlled, the flow rate is further controlled, the bandwidth is more fully utilized, and the transmission efficiency is improved.

Embodiment 3

Referring to FIG. 5, an embodiment of the present invention provides a compression end device that optimizes a compressed real-time protocol. The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The compression end device 500 includes:

a detecting module 501, configured to detect a link available bandwidth;

The comparing module 502 is configured to compare whether the available bandwidth is less than or equal to a preset ratio;

For example, the preset ratio can be set to 20% according to the actual usage of the bandwidth;

The response module 503 is configured to determine, according to the comparison result of the comparison module 502, whether to respond to the context state message; if the comparison result is that the available bandwidth is greater than a preset ratio, the response module 503 notifies the upper CPU, so that the upper CPU notifies the underlying NP. And responding to the context state message; if the comparison result is that the available bandwidth is less than or equal to the preset ratio, the response module 503 notifies the upper layer CPU, so that the upper layer CPU notifies the underlying NP, and prohibits the response to the context state message.

The upper layer CPU may notify the underlying NP by setting the preset flag bit to allow the status of the context state message or the state of the response context message.

In other embodiments, the compression end device 500 may further include:

The complete header packet module 504 is configured to send a FULL HEAD message to the decompression end device when the response module 503 determines to respond to the context status message;

The flow control module 505 is configured to control the traffic when the response module 503 determines that the context state message is not to be responded, and adjust the traffic of the packet to adapt the traffic of the packet to the available bandwidth. Further, the flow control module 505 can regulate the flow by reducing the flow rate of the flow source.

In this embodiment, when traffic congestion occurs on a narrowband link to which the CRTP compression protocol is applied, the avalanche effect of congestion caused by the original protocol algorithm can be effectively alleviated, and the bandwidth can be fully utilized to improve transmission efficiency.

The above described specific embodiments of the present invention are further described in detail, and are intended to be illustrative of the embodiments of the present invention. The scope of the protection, any modifications, equivalents, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

Rights request

1. An optimization method for compressing a real-time protocol, the method comprising:

Detect the available bandwidth of the link;

If the available bandwidth is less than or equal to a preset ratio, the upper layer central processor is notified to prohibit the response to the context message.

The method according to claim 1, wherein the method further comprises: receiving a context status message sent by the decompressing end.

3. The method according to claim 1, wherein the predetermined ratio is 20%.

The method according to claim 1, wherein the method further comprises: if the available bandwidth is greater than the preset ratio, notifying the upper layer central processor to allow response to the context status message.

The method according to claim 4, wherein the method further comprises: if the available bandwidth is greater than a preset ratio, sending a complete header message to the decompressing end.

The method according to claim 1, wherein the method further comprises: adjusting the traffic to adapt the traffic to the available bandwidth when the available bandwidth is less than or equal to the predetermined ratio.

7. The method according to claim 6, wherein the adjusting the flow rate comprises: reducing a flow rate of the flow source end.

The method according to claim 1, wherein the detection link available bandwidth is: reading the first packet byte number ByteJO sent by the link at the first predetermined time TO, at the second predetermined time T1 reads the second packet byte number Byte_T1 sent by the link, and the available bandwidth is (Byt _e _Tl-B _y te_T0) / (T1-T0).

9. A compression end device, the device comprising:

a detecting module, configured to detect a bandwidth available to the link;

a comparison module, configured to compare whether the available bandwidth is less than or equal to a preset ratio;

The response module is configured to determine, according to the comparison result of the comparison module, whether to respond to the context status message, and notify the upper layer central processing when the comparison result of the comparison module is that the available bandwidth is less than or equal to the preset ratio So that the upper layer central processor notifies the underlying network processor to disable response to the context status message.

The device according to claim 9, wherein the response module is further configured to notify the upper layer central processing when the comparison result of the comparison module is that the available bandwidth is greater than the preset ratio So that the upper layer central processor notifies the underlying network processor to respond to the context status message.

The device according to claim 9, wherein the device further comprises:

a flow control module, configured to control traffic when the response module determines that the response to the context status message is prohibited, and adjusts the report The traffic of the text is such that the traffic of the message adapts to the available bandwidth.

The device according to claim 10, wherein the device further comprises:

The complete header packet module is configured to send a complete header message to the decompressed end when the response module determines to respond to the context status message.