Huawei U-SYS MRS6100 Technical Manual page 50

Technical Manual
U-SYS MRS6100 Media Resource Server
The 2nd line: The Call-ID is a265.
The 3rd line: the local connection options. The Call Agent suggests MRS to set the
compression algorithm to PCMA and set the encapsulation delay to 20 milliseconds.
The 4th line: The connection mode is sendrecv, that is, both sending and receiving of
data packets are allowed.
The 5th line: Null, indicating that the following is the SDP session description.
The 6th line: The version of SDP protocol is 0. It is the local connection descriptor.
The 7th line: The field c identifies the connection information. IN refers to network
indicator in the form of a text string. The currently defined IN is Internet. IP4 indicates
that the connection address type is IP4. 182.20.40.4 represents the network address
of the MRS peer gateway that has a connection with MGC.
The 8th line: media description. The field audio refers to the media type. 30002 is the
No. of the transport layer port to which media streams are transmitted. RTP/AVP is
the transport layer protocol. The field 8 corresponds to the media coding/encoding
format PCMA.
CRCX ACK encoding
200 693585490 OK
I:1607901
v=0
c=IN IP4 182.20.50.101
m=audio 10000 RTP/AVP 8 0 18 4
a=ptime:20
The field 200 indicates the successful receipt of the command. 693585490 is a
transaction identifier, the same as the transaction identifier contained in the command
that triggers this response. OK is a comment. It indicates that MG has received and is
processing the request. The field I is the connection identifier. MRS returns the
connection identifier to MGC after establishing a connection. In addition, MRS returns
the SDP session description, MRS port number and IP address.
2) Event 2: After establishing a connection, MGC sends the RQNT announcement
playing command to MRS.
RQNT encoding
RQNT 170983909 ms/cnf/1@mr6100.com MGCP 1.0
X:1e000424
R:A/of(N),A/oc
S:BAU/pa@0(an=HWF001000B?lang=chi iv=10 it=20)
Huawei Technologies Proprietary
5-25
Chapter 5 MGCP and SIP