CN1937620A - Media flow transmission address consulting method - Google Patents
Media flow transmission address consulting method Download PDFInfo
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- CN1937620A CN1937620A CN200510106295.1A CN200510106295A CN1937620A CN 1937620 A CN1937620 A CN 1937620A CN 200510106295 A CN200510106295 A CN 200510106295A CN 1937620 A CN1937620 A CN 1937620A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
- H04L65/10—Architectures or entities
- H04L65/102—Gateways
- H04L65/1043—Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
- H04L65/1066—Session management
- H04L65/1101—Session protocols
- H04L65/1104—Session initiation protocol [SIP]
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- 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
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Abstract
The invention discloses a media steam transmission address negotiating method, transmitting a message containing session description protocol (SDP) information by first equipment to second equipment, respectively appointing corresponding transmission addresses in the SDP information in accordance with partial or all coding-decoding formats the first equipment desire to build; the second equipment obtains various coding-decoding formats of the media flow desired and corresponding transmission addresses from the SDP information in the received message, determines a desired coding-decoding format and returns a response message containing the desired coding-decoding format and corresponding transmission address.
Description
Technical field
The present invention relates to communication technical field, relate in particular to the machinery of consultation of dialogue-based description agreement (SDP) media flow transmission address.
Background technology
The multimedia service of IP based network is obtaining application more and more widely at present.Technologically speaking, the realization of this business mainly comprises the signaling control section, medium are handled and transmit two aspects.Wherein signaling moiety is used for setting up session relationship between communication entity, and finishes the negotiation of intercommunication parameter.The result that mainly consult according to signaling the medium processing section adopts specific Media Stream packing to carry out communicating by letter of Media Stream with transmission means.Mainly adopt RTP (Real-time Transport Protocol) for the transmission of real-time media streams such as audio frequency or video, then adopt TCP etc. can guarantee the agreement of reliable transmission usually for the media flow transmission of data services such as electronic whiteboard.
At present in command negotiation process to the description of Media Stream parameter mainly based on the SDP agreement, both sides finish mailing address by SDP negotiation, Media Stream type, the isoparametric negotiation of coding/decoding capability.Wherein the conventional method of mailing address negotiation is: provide the side of SDP to carry own Media Stream ability and the pairing mailing address of being supported of each bar Media Stream.After both sides finished SDP negotiation, Media Stream just sent to the address of appointment.
The SDP agreement is based on the media capability of text and describes agreement, and the mode that it adopts " attribute-name=parameter ... " is described the media capability of communication entity.Mainly be defined as follows:
Session?description
v＝(protocol?version)
o＝(owner/creator?and?session?identifier)
s＝(session?name)
c＝
*(connection?information-not?required?if?included?in?all?media)
Zero?or?more?media?descriptions(see?below)
Media?description
m＝(media?name?and?transport?address)
c＝
*(connection?information-optional?if?included?at?session-level)
a＝
*(zero?or?more?media?attribute?lines)
Parameter declaration relevant with the Media Stream mailing address in it is as follows:
c＝<network?type><address?type><connection?address>
Can be used for representing the normally IPV4 of link address, IPV6 or domain name (not comprising transport layer port number), if " c=" property column is placed on the conversation description part of SDP, then all effective to all follow-up Media Streams, unless certain bar Media Stream has " c=" attribute of oneself; If being placed on the media description part of SDP, " c=" property column represents that this address is only effective at his pairing specific that Media Stream (m is capable).
Defined in the Session Initiation Protocol and how to have utilized SDP to carry out media capability (comprising the media communication address) negotiation method, its canonical process following (having omitted incoherent header field) with the present invention:
Step 1: caller sip user (a@domain.com) initiates a session request to called (b@domain.com) by INVITE, wherein comprises the media capability (comprising the media communication address) of caller.Message is as follows:
INVITE?sip：b@domain.com?SIP/2.0
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>
Content-Type：application/sdp
Content-Length：...
v＝0
o＝a?2890844526?2890844526?IN?IP4?10.0.0.1
s＝Session?SDP
c＝IN?IP4?10.0.0.1
t＝0?0
m＝audio?49170?RTP/AVP?0
The wherein capable information representation of c, the Media Stream receiver address of caller is 10.0.0.1; The information representation that m is capable, caller wish to set up an audio medium stream, and encoding and decoding are 0 (PCMU), and the receiving port number of these medium is 49170.That is to say that the calling party wishes that it is 49170 that the opposite end sends to port numbers with Media Stream, the IP address is the address of 10.0.0.1.
Step 2: called sip user (b@domain.com) is then replied to called (b@domain.com) by 200 OK message if be ready to accept this calling after receiving INVITE, wherein comprises called media capability.Message is as follows:
SIP/2.0?200?OK
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Content-Type：application/sdp
Content-Length：...
v＝0
o＝b?4702834?3847012?IN?IP4?10.0.0.2
s＝Session?SDP
c＝IN?IP4?10.0.0.2
t＝0?0
m＝audio?1234?RTP/AVP?0
The wherein capable information representation of c, called Media Stream receiver address is 10.0.0.2; An audio medium stream is set up in the information representation that m is capable, called agreement, and encoding and decoding are 0 (PCMU), and the receiving port number of these medium is 1234.That is to say that the callee wishes that it is 1234 that the opposite end sends to port numbers with Media Stream, the IP address is the address of 10.0.0.2.
Step 3: caller sip user (a@domain.com) receives 200 backs and represents to have acknowledged receipt of 200 OK to ACK message of called transmission.Message is as follows:
ACK?b@domain.com?SIP/2.0
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Step 4: after above process was finished, the calling and called both sides finished session foundation and media consultation process, sent Media Stream to IP address that is used for media flow transmission and the port numbers that the opposite end provides respectively according to the Media Stream parameter of consulting to determine separately.
In existing procedure, it is capable by the m=that defines in the SDP agreement that both sides carry out Media Stream packaging time length capability negotiation, and the capable parameter of carrying of c=is finished, and its syntax format is as follows:
m＝<media><port><transport><fmt?list>
Wherein＜and port〉pairing media receiving end slogan of Media Stream of expression;
c＝<network?type><address?type><connection?address>
C=is capable to can be used for representing the local terminal link address, IPV4 normally, IPV6 or domain name (noting: do not comprise transport layer port number) are if c=is placed on the conversation description part of SDP, and be then all effective to following all Media Streams (m is capable), unless certain bar Media Stream has the c=attribute of oneself; If being placed on the media description part of SDP, c=represents that this address is only effective at his pairing specific that Media Stream (m is capable).
For example:
(1) situation of many shared link addresses of Media Stream
v＝0
o＝b?4702834?3847012?IN?IP4?10.0.0.2
s＝Session?SDP
c＝IN?IP4?10.0.0.2
m＝audio?1234?RTP/AVP?0?4?8
m＝video?5678?RTP/AVP?31?32
Article one, the receiving port number of Media Stream is 1234, and second is 5678, but the IP address all is 10.0.0.2
(2) Media Stream has the situation of the specific link address of oneself
v＝0
o＝b?4702834?3847012?IN?IP4?10.0.0.2
s＝Session?SDP
c＝IN?IP4?10.0.0.2
m＝audio?1234?RTP/AVP?0?4?8
c＝IN?IP4?10.0.0.3
m＝video?5678?RTP/AVP?31?32
Article one, the receiving port number of Media Stream is 1234, because to follow a c=capable in the back, so its IP address is 10.0.0.3; The receiving port number of second Media Stream is 5678, and the IP address is because c=of no use special appointment in back then still adopts session to represent the default link address 10.0.0.2 of the c=line display of part.
From the above, there are the following problems for present Media Stream address negotiation mechanism:
(1) owing in a Media Stream (m is capable) is described, can only fill in a port numbers, therefore, terminal can be supported multiple encoding and decoding at a Media Stream, and wishes to select to utilize existing negotiation mechanism to realize under the different receiving ports according to different encoding and decoding.
(2) because a Media Stream (m is capable) can only adopt a c=line display link address parameter, for a certain Media Stream, when terminal wishes to select different IP addresses to transmit according to different encoding and decoding, equally can't be supported.
Summary of the invention
The invention provides a kind of media flow transmission address machinery of consultation, to solve the problem that to support in the existing media flow transmission address negotiation at the different code/decode format given transmission address of Media Stream.
The invention provides following technical scheme:
A kind of machinery of consultation of media flow transmission address comprises the steps:
First equipment sends the message that comprises Session Description Protocol (SDP) information to second equipment, and the part or all of code/decode format of the Media Stream that need set up at this first equipment in this SDP information is specified corresponding transport address respectively;
Second equipment obtains each code/decode format and the corresponding transport address that needs the Media Stream set up from the SDP information of the message that receives, determine the code/decode format that this equipment is wished and return the response message that comprises this code/decode format and corresponding transport address.
Wherein:
Described second equipment is behind the response message of the message that receives the transmission of first equipment or this message, the code/decode format of the present networks equipment support that provides and corresponding transport addresses information can be well-determined a kind of encoding and decoding and transport address thereof, also can one be multiple encoding and decoding all supports of local terminal or that may adopt and corresponding transport address thereof.
The network equipment that transmits described message between first equipment and second equipment joins each code/decode format of present networks equipment support media stream and the transport address of correspondence in the SDP information of message behind the response message of the message that receives the transmission of first equipment or this message.
The described network equipment determines that the code/decode format of second choice of equipment is the code/decode format that first equipment is supported, then directly sets up the Media Stream of wishing between first equipment and second equipment.
The described network equipment determines that the code/decode format of second choice of equipment is supported for present networks equipment but the unsupported code/decode format of first equipment is then set up Media Stream and finished encoding and decoding conversion with first equipment and second equipment respectively.
Described message is the SIP signaling message; Perhaps, described message is the MGCP signaling message; Perhaps, described message is signaling message H.248.
Media description at SDP is partly expanded the attribute definition that comprises media stream code/decode format at least, describes code/decode format and corresponding transport address by this attribute definition.
If not explicit given transmission address in the described attribute definition then obtains from corresponding attribute definition by the SDP standard.
The present invention is owing to supported to consult based on other transport address of encoding and decoding level, transfer gateway can add own coding/decoding information and the transport address of being supported thereof by simple in SDP, come to reach according to the media capability whether the calling and called both sides have a coupling session flow process of flexible control needs encoding and decoding conversion with this.
Adopt the present invention, make the SIP of employing based on the SDP agreement, MGCP, H.248 the communication equipment in the communication network of agreement can be held consultation to the pairing media delivery of different encoding and decoding address in the Media Stream.
Description of drawings
Fig. 1 is a process chart of consulting the Media Stream address between the calling and called;
Fig. 2 is the schematic diagram that intelligent encoding and decoding conversion gateway participates in the conversation media capability negotiation;
Fig. 3 is the flow chart of media capability negotiation under the unmatched situation of calling and called ability;
Fig. 4 is the flow chart of media capability negotiation under the situation of calling and called capabilities match.
Embodiment
In order to support multiple encoding and decoding at a Media Stream, and wish to select under the situation of different transport addresses according to different encoding and decoding, make the negotiation that to finish media flow transmission address between the equipment that participates in media flow transmission, the present invention is in Session Description Protocol (SDP) information that sip message comprised, at hope or be ready that the part or all of code/decode format of the Media Stream set up specifies corresponding transport address respectively, make the equipment that participates in consulting to select corresponding transport address according to different code/decode formats.
For a side who initiate to consult, in the SDP of SIP signaling message part, the part or all of code/decode format of the Media Stream of setting up at hope is specified the transport address of correspondence respectively; Receive a side of SIP signaling message, can therefrom select a kind of code/decode format of oneself wishing and notify the other side by response message, also can be in the SDP of the response message that sends to the other side part, specify corresponding transport address respectively at the part or all of code/decode format of the Media Stream of being ready to set up, a side who initiates to consult then selects a kind of code/decode format of hope and notifies the other side, and the other side confirms.
Generally speaking, borde gateway between two heterogeneous networks territories (processing capacity that comprises signalling interworking and/or medium intercommunication here in logic) can have the function of encoding and decoding conversion, need between the gateway in across a network territory by the borde gateway media stream, when the media capability between the equipment does not match, can finish the foundation of session by medium conversion facilities.Therefore, between two equipment of gateway forwards during the sip message relevant, when in this message, adding own encoding and decoding of supporting, the transport address of the encoding and decoding correspondence that self increases newly is also added in the message with the Media Stream address negotiation.Selected not support the code/decode format of other end equipment if select a method, apparatus of code/decode format, what then select is the code/decode format that transfer gateway provides, because the encoding and decoding correspondence that transfer gateway is newly-increased is its transport address, therefore select a method, apparatus of code/decode format will set up and transfer gateway between medium connect, between equipment, finish the code/decode format conversion by transfer gateway; If what select is the code/decode format (at this moment not needing to change) that other end equipment is supported, then directly sets up medium between the equipment and connect.
The present invention partly expands the definition line that comprises media stream code/decode format at least at the media description of SDP, describes code/decode format and corresponding transport address by this definition line.According to the code/decode format of equipment, the description of a Media Stream can have one or more such definition line.
The media capability negotiation that present embodiment is set up process with the SIP session be example the present invention is described in detail, in the message examples of follow-up description, omitted relevant code/decode format with the present invention and transport address and defined incoherent header field.
In the present embodiment, expand in the following way in the SDP agreement, represent the address information that a certain specific encoding and decoding are adopted at the description of Media Stream address information:
a＝fmtp：<format>[addrtype＝<addrtype>][c＝<connection?attribute>][port＝<port>]
Wherein can to specify this address be rtp to addrtype, rtcp or other types, and to be defaulted as be the default addresses for use type of this Media Stream if do not fill out.
Wherein the form of " c=" can be continued to use the syntactic definition of going at " c=" among the RFC2327; Should " c=" be optionally, if do not fill out then represent that the transport address of this encoding and decoding correspondence still obtains from " c=" row of SDP according to original SDP standard; Wherein " port=" also is optionally, if do not fill out then represent that this encoding and decoding corresponding port number still obtains from corresponding m=is capable according to original SDP standard.
For example:
m＝audio?1234?RTP/AVP?0?4?8?18；
c＝IN?IP4?10.0.0.0；
A=fmtp:0 c=IN IP4 10.0.0.1 port=1235//these encoding and decoding of appointment have specific link address and port;
A=fmtp:0 addrtype=rtcp c=IN IP4 10.0.0.1 port=1236//these encoding and decoding of appointment have specific rtcp link address and port numbers;
A=fmtp:4 c=IN IP4 10.0.0.2//these encoding and decoding of appointment have specific link address;
A=fmtp:8 port=5678//these encoding and decoding of appointment have specific port numbers.
Consult shown in Figure 1ly, the handling process of consulting the Media Stream address between the typical calling and called is as follows:
Step 1: caller sip user (a@domain.com) initiates a session request to called (b@domain.com) by INVITE, wherein comprises the media capability (comprising the media communication address) of caller.Message is as follows:
INVITE?sips：b@domain.com?SIP/2.0
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>
Content-Type：application/sdp
Content-Length：...
v＝0
o＝a?2890844526?2890844526?IN?IP4?10.0.0.1
s＝Session?SDP
c＝IN?IP4?10.0.0.1
t＝0?0
m＝audio?49170?RTP/AVP?0?4?8
a＝fmtp：0?port＝50000
a＝fmtp：8?port＝55000
The wherein capable information representation of c, the Media Stream receiver address of caller is 10.0.0.1; The information representation that m is capable, caller wish to set up an audio medium stream, and encoding and decoding can be 0 (PCMU), 4 (G.723), and 8 (PCMA), the default receiving port number of these medium is 49170.Below a=capable to have specified the receiving port number of encoding and decoding 0 (PCMU) respectively separately be 50000, the receiving port number of encoding and decoding 8 (PCMA) is 55000.And encoding and decoding 4 (G.723) are not so specify the default port numbers 49170 that port numbers still adopts this Media Stream.
Step 2: called sip user (b@domain.com) is then replied to called (b@domain.com) by 200 OK message if be ready to accept this calling after receiving INVITE, wherein comprises called media capability.Message is as follows:
SIP/2.0?200?OK
From：a<sip：a@domain.com>；tag＝1234567
To：bsip：b@domain.com>；tag＝137480
Content-Type：application/sdp
Content-Length：...
v＝0
o＝b?4702834?3847012?IN?IP4?10.0.0.2
s＝Session?SDP
c＝IN?IP4?10.0.0.2
t＝0?0
m＝audio?1234?RTP/AVP?0
The wherein capable information representation of c, called Media Stream receiver address is 10.0.0.2; An audio medium stream is set up in the information representation that m is capable, called agreement, and encoding and decoding are 0 (PCMU), and the receiving port number of these medium is 1234.That is to say that the callee wishes that it is 1234 that the opposite end sends to port numbers with Media Stream, the IP address is the address of 10.0.0.2.
Step 3: caller sip user (a@domain.com) receives 200 backs and represents to have acknowledged receipt of 200 OK to ACK message of called transmission.Message is as follows:
ACK?b@domain.com?SIP/2.0
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Step 4: after above process was finished, the calling and called both sides finished session foundation and media consultation process, sent Media Stream to IP address that is used for media flow transmission and the port numbers that the opposite end provides respectively according to the Media Stream parameter of consulting to determine separately.
After the above-mentioned negotiation, called selection be encoding and decoding 0 (PCMU), according to the SDP information that caller provides, it should send to Media Stream No. 50000 ports of caller.If called selection encoding and decoding 8 (PCMA), that just should send to 55000 ports of caller.
The embodiment that is applied as with intelligent encoding and decoding conversion gateway participation conversation media capability negotiation describes below, consults shown in Figure 2.
Owing to the specific transport address that can describe each concrete encoding and decoding in SDP description part, so transfer gateway is also adding the transport address of the encoding and decoding correspondence that self increases newly to come in when sip message adds the encoding and decoding of oneself supporting.Can finish the foundation of session when caller and called media capability do not match by medium conversion facilities, for example: codec1 is supported in caller; Called support codec2, and transfer gateway support conversion between the two, so to set up situation be caller to Shi Ji media channel the medium of codec1 are sent to gateway is converted to and is transmitted to after the codec2 calledly, vice versa.If both capabilities match then can not need to carry out encoding and decoding conversion, Media Stream still can directly be set up between calling and called.
Consult shown in Figure 3, for the unmatched situation of calling and called ability, the main flow process of its negotiation following (wherein having omitted and consulted incoherent SIP and SDP message header field):
Step 1: caller sip user (a@domain.com) initiates a session request to called (b@domain.com) by INVITE, and this message wherein comprises the media capability (comprising the media communication address) of Calling Side through transfer gateway.Message is as follows:
INVITE?sip：b@domain.com?SIP/2.0
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>
Content-Type：application/sdp
Content-Length：...
v＝0
o＝a?2890844526?2890844526?IN?IP4?10.0.0.1
s＝Session?SDP
t＝0?0
m＝audio?1234?RTP/AVP?0
a＝frntp：0?c＝IN?IP4?10.0.0.1
The Media Stream that it is 0 (PCMU) that the wherein information representation of SDP, caller are wished to set up encoding and decoding, its receiver address is 10.0.0.1, port is 1234.
Step 2: transfer gateway is transmitted this INVITE to callee side, but consider that because calling and called both sides ability does not match and contingent encoding and decoding conversion transfer gateway adds the own more coding/decoding capability of being supported (comprising the media communication address) in SDP.Message is as follows:
INVITE?sips：b@domain.com?SIP/2.0
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>
Content-Type：application/sdp
Content-Length：...
v＝0
o＝a?2890844526?2890844526?IN?IP4?10.0.0.1
s＝Session?SDP
t＝0?0
m＝audio?1234?RTP/AVP?0?4
a＝fmtp：0?c＝IN?IP4?10.0.0.1
a＝fmtp：4?c＝IN?IP4?11.0.0.1?port＝2345
Wherein to have increased own encoding and decoding 4 (G.723) and the transport address 11.0.0.1 port numbers of being supported be 2345 to transfer gateway.
Step 3: called sip user (b@domain.com) is then replied to called (b@domain.com) by 200 OK message if be ready to accept this calling after receiving INVITE, and message returns to transfer gateway.Owing to support encoding and decoding 4 for called, thus it to return oneself media capability message as follows:
SIP/2.0?200?OK
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Content-Type：application/sdp
Content-Length：...
v＝0
o＝b?4702834?3847012?IN?IP4?10.0.0.8
s＝Session?SDP
c＝IN?IP4?10.0.0.8
t＝0?0
m＝audio?3456?RTP/AVP?4
The wherein capable information representation of c, called Media Stream receiver address is 10.0.0.8; An audio medium stream is set up in the information representation that m is capable, called agreement, and encoding and decoding are 4 (G.723), and the receiving port number of these medium is 3456.That is to say that the callee wishes that it is 3456 that the opposite end sends to port numbers with Media Stream, the IP address is the address of 10.0.0.8.
Step 4: transfer gateway is transmitted response message to caller sip user (a@domain.com).Because called selection is the encoding and decoding 4 that oneself increase, and encoding and decoding 0 are only supported in caller, judgement need be carried out encoding and decoding conversion, because caller only supports encoding and decoding 0, so it returns the media channel address information of the processing encoding and decoding 0 that are used for encoding and decoding conversion of the distribution of oneself.Message is as follows:
SIP/2.0?200?OK
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Content-Type：application/sdp
Content-Length：...
v＝0
o＝b?4702834?3847012?IN?IP4?10.0.0.8
s＝Session?SDP
c＝IN?IP4?11.0.0.1
t＝0?0
m＝audio?4567?RTP/AVP?0
The wherein capable information representation of c, called Media Stream receiver address is 11.0.0.1; An audio medium stream is set up in the information representation that m is capable, called agreement, and encoding and decoding are 0 (PCMU), and the receiving port number of these medium is 4567.That is to say that the callee wishes that it is 4567 that the opposite end sends to port numbers with Media Stream, the IP address is the address of 11.0.0.1.
Step 5: caller sip user (a@domain.com) receives 200 backs and represents to have acknowledged receipt of 200 OK to ACK message of callee side transmission.Message sends to transfer gateway, and is as follows:
ACK?b@domain.com?SIP/2.0
Via：SIP/2.0/UDP?a@domain.com：5061；branch＝z9hG4bK74bf9
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Step 6: transfer gateway is to called forwarding ACK, and message is as follows:
ACK?b@domain.com?SIP/2.0
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Step 7: after above process was finished, the calling and called both sides had set up medium with transfer gateway in fact respectively and have been connected, and adopted encoding and decoding 0 between Calling Side and the transfer gateway, adopted encoding and decoding 4 between callee side and the transfer gateway.
Consult shown in Figure 4, for the situation of calling and called capabilities match, the main flow process of its negotiation following (wherein having omitted and consulted incoherent SIP and SDP message header field):
The difference of this handling process and flow process shown in Figure 3 is, though transfer gateway has increased the ability of own support, but owing to have common ability between callee side and the Calling Side, the ability that therefore called final selection caller is supported, thereby directly set up with caller between medium be connected.
Step 1-2: caller-transfer gateway, the processing procedure of transfer gateway-called is identical with the processing in Fig. 3 flow process.
Step 3: called sip user (b@domain.com) is then replied to called (b@domain.com) by 200 OK message if be ready to accept this calling after receiving INVITE, and message returns to transfer gateway.Because called support encoding and decoding 0, thus it to return oneself media capability message as follows:
SIP/2.0?200?OK
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Content-Type：application/sdp
Content-Length：...
v＝0
o＝b?4702834?3847012?IN?IP4?10.0.0.8
s＝Session?SDP
c＝IN?IP4?10.0.0.8
t＝0?0
m＝audio?3456?RTP/AVP?0
The wherein capable information representation of c, called Media Stream receiver address is 10.0.0.8; An audio medium stream is set up in the information representation that m is capable, called agreement, and encoding and decoding are 0 (PCMU), and the receiving port number of these medium is 3456.That is to say that the callee wishes that it is 3456 that the opposite end sends to port numbers with Media Stream, the IP address is the address of 10.0.0.8.
Step 4: transfer gateway is transmitted response message to caller sip user (a@domain.com).Because called selection is not the encoding and decoding 4 that oneself increase, but the encoding and decoding 0 that caller is supported, judging does not need to carry out encoding and decoding conversion, and it directly returns to Calling Side with called SDP information.Message is as follows:
SIP/2.0?200?OK
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Content-Type：application/sdp
Content-Length：...
v＝0
o＝b?4702834?3847012?IN?IP4?10.0.0.8
s＝Session?SDP
c＝IN?IP4?10.0.0.8
t＝0?0
m＝audio?3456?RTP/AVP?0
The wherein capable information representation of c, called Media Stream receiver address is 10.0.0.8; An audio medium stream is set up in the information representation that m is capable, called agreement, and encoding and decoding are 0 (PCMU), and the receiving port number of these medium is 4567.That is to say that the callee wishes that it is 4567 that the opposite end sends to port numbers with Media Stream, the IP address is the address of 10.0.0.8.
Step 5-6: caller is to called transmission ACK message.
Step 7: after above process was finished, the calling and called both sides were not because the coding/decoding capability unanimity need be carried out media conversion by transfer gateway, and Media Stream is directly to set up between calling and called.
Method of the present invention is equally applicable to the application that media device is supported many network addresss.If the caller medium processing device is a gateway device of supporting many IP address, different integrated circuit boards provides dissimilar encoding and decoding supports, and different integrated circuit boards provides different network interfaces (having the independently network address).At this moment just need in the media capability negotiation process, specify the network address of corresponding integrated circuit board at different coding/decoding capabilities.Equally also can specify different port numbers according to the strategy of realizing.As:
The link address of encoding and decoding 0 (PCMU) and 8 (PCMA) is 10.0.0.1
The link address of encoding and decoding 4 (G.723) is 10.0.0.2
The link address of encoding and decoding 18 (G.729) is 10.0.0.3
During using, many network addresss realize the flow process following (seeing also shown in Figure 1) of negotiation:
Step 1: caller sip user (a@domain.com) initiates a session request to called (b@domain.com) by INVITE, wherein comprises the media capability (comprising the media communication address) of Calling Side gateway.Message is as follows:
INVITE?sips：b@domain.com?SIP/2.0
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>
Content-Type：application/sdp
Content-Length：...
v＝0
o＝a?2890844526?2890844526?IN?IP4?10.0.0.1
s＝Session?SDP
t＝0?0
m＝audio?1234?RTP/AVP?0?8?4?18
c＝IN?IP4?10.0.0.1
a＝fmtp：4?c＝IN?IP4?10.0.0.2
a＝fmtp：8?c＝IN?IP4?10.0.0.3
The wherein capable information representation of c, the default receiver address of the Media Stream of caller is 10.0.0.1; The information representation that m is capable, caller wish to set up an audio medium stream, and encoding and decoding can be 0 (PCMU), 4 (G.723), 8 (PCMA), 18 (G.729).The default receiving port number of this Media Stream is 1234.Below a=capable to have specified the reception IP address of encoding and decoding 4 (G.723) respectively separately be 10.0.0.2, the reception IP address of encoding and decoding 18 (G.729) is 10.0.0.3.And encoding and decoding 0 (PCMU), 8 (PCMA) do not specify, so the default addresses for use 10.0.0.1 of this Media Stream is still adopted in the IP address.
Step 2: called sip user (b@domain.com) is then replied to called (b@domain.com) by 200 OK message if be ready to accept this calling after receiving INVITE, wherein comprises called media capability.Message is as follows:
SIP/2.0?200?OK
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Content-Type：application/sdp
Content-Length：...
v＝0
o＝b?4702834?3847012?IN?IP4?10.0.0.8
s＝Session?SDP
c＝IN?IP4?10.0.0.8
t＝0?0
m＝audio?5678?RTP/AVP?0
The wherein capable information representation of c, called Media Stream receiver address is 10.0.0.8; An audio medium stream is set up in the information representation that m is capable, called agreement, and encoding and decoding are 0 (PCMU), and the receiving port number of these medium is 1234.That is to say that the callee wishes that it is 1234 that the opposite end sends to port numbers with Media Stream, the IP address is the address of 10.0.0.2.
Step 3: caller sip user (a@domain.com) receives 200 backs and represents to have acknowledged receipt of 200 OK to ACK message of called transmission.Message is as follows:
ACK?b@domain.com?SIP/2.0
From：a<sip：a@domain.com>；tag＝1234567
To：b<sip：b@domain.com>；tag＝137480
Step 4: after above process was finished, the calling and called both sides finished session foundation and media consultation process, sent Media Stream to IP address that is used for media flow transmission and the port numbers that the opposite end provides respectively according to the Media Stream parameter of consulting to determine separately.
For called negotiations process of in response message, carrying multiple or whole code/decode formats that local terminal supports and corresponding transport address and in like manner above-mentioned, repeat no more.
Though above-mentionedly the present invention is illustrated that be not limited to this, the present invention is equally applicable to adopt the MGCP based on the SDP agreement with Session Initiation Protocol message, H.248 in the communication network of agreement, by MGCP or H.248 agreement realize with in like manner above-mentioned.Negotiations process about the encoding and decoding transport address among the present invention can be included in application corresponding layer protocol (SIP, MGCP, H.248 etc.) in the various SDP negotiation scene processes that allowed, these processes include but not limited to: session is set up, session modification, initiating capacity negotiation etc. again.
Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.
Claims (10)
1, a kind of machinery of consultation of media flow transmission address is characterized in that, comprises the steps:
First equipment sends the message that comprises Session Description Protocol (SDP) information to second equipment, and the part or all of code/decode format of the Media Stream that need set up at this first equipment in this SDP information is specified corresponding transport address respectively;
Second equipment obtains each code/decode format and the corresponding transport address that needs the Media Stream set up from the SDP information of the message that receives, and returns the response message that comprises code/decode format that this equipment wishes and corresponding transport address.
2, the method for claim 1 is characterized in that, the code/decode format that second equipment is wished is the part or all of code/decode format in the code/decode format supported of second equipment.
3, the method for claim 1, it is characterized in that, the network equipment that transmits described message between first equipment and second equipment joins each code/decode format of present networks equipment support media stream and the transport address of correspondence in the SDP information of message behind the response message of the message that receives the transmission of first equipment or this message.
4, method as claimed in claim 3 is characterized in that, the described network equipment determines that the code/decode format of second choice of equipment is the code/decode format that first equipment is supported, then directly sets up the Media Stream of wishing between first equipment and second equipment.
5, method as claimed in claim 3, it is characterized in that, the described network equipment determines that the code/decode format of second choice of equipment is supported for present networks equipment but the unsupported code/decode format of first equipment is then set up Media Stream and finished encoding and decoding conversion with first equipment and second equipment respectively.
6, the method for claim 1 is characterized in that, described transport address is the IP address; Perhaps, described transport address is a port numbers; Perhaps, described transport address is IP address and port numbers.
7, the method for claim 1 is characterized in that, described message is the SIP signaling message; Perhaps, described message is the MGCP signaling message; Perhaps, described message is signaling message H.248.
8, the method for claim 1 is characterized in that, the negotiations process that first equipment and second equipment carry out the encoding and decoding transport address can be included in the various SDP negotiation processes that the application corresponding layer protocol allowed.
9, as each described method of claim 1 to 8, it is characterized in that, partly expand the attribute definition that comprises media stream code/decode format at least, describe code/decode format and corresponding transport address by this attribute definition at the media description of SDP.
10, method as claimed in claim 9 is characterized in that, if not explicit given transmission address in the described attribute definition then obtains from corresponding attribute definition by the SDP standard.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200510106295.1A CN1937620A (en) | 2005-09-23 | 2005-09-30 | Media flow transmission address consulting method |
| PCT/CN2006/002495 WO2007033606A1 (en) | 2005-09-23 | 2006-09-22 | Negotiation method for transmission address of media stream |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200510104899.2 | 2005-09-23 | ||
| CN200510104899 | 2005-09-23 | ||
| CN200510106295.1A CN1937620A (en) | 2005-09-23 | 2005-09-30 | Media flow transmission address consulting method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1937620A true CN1937620A (en) | 2007-03-28 |
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ID=37888559
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200510106295.1A Pending CN1937620A (en) | 2005-09-23 | 2005-09-30 | Media flow transmission address consulting method |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN1937620A (en) |
| WO (1) | WO2007033606A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101141807B (en) * | 2007-08-25 | 2011-10-26 | 中兴通讯股份有限公司 | Coding/decoding negotiation method |
| CN110062056A (en) * | 2018-01-19 | 2019-07-26 | 中兴通讯股份有限公司 | Method for network address translation and device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI20011962A0 (en) * | 2001-10-09 | 2001-10-09 | Nokia Corp | The code converter arrangement |
| CN1306779C (en) * | 2003-03-18 | 2007-03-21 | 华为技术有限公司 | Medium flow processing method in IP network |
| KR20050080619A (en) * | 2004-02-10 | 2005-08-17 | 주식회사 케이티 | System for processing call using subscriber codec providing server in session initiation protocol and method for codec matching the same |
-
2005
- 2005-09-30 CN CN200510106295.1A patent/CN1937620A/en active Pending
-
2006
- 2006-09-22 WO PCT/CN2006/002495 patent/WO2007033606A1/en active Application Filing
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101141807B (en) * | 2007-08-25 | 2011-10-26 | 中兴通讯股份有限公司 | Coding/decoding negotiation method |
| CN110062056A (en) * | 2018-01-19 | 2019-07-26 | 中兴通讯股份有限公司 | Method for network address translation and device |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2007033606A1 (en) | 2007-03-29 |
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