AudioCodes E-SBC User Manual page 509

CHAPTER 20 SIP Definitions
● The realm return by the proxy is "AudioCodes.com".
● The password from the ini file is "AudioCodes".
● The equation to be evaluated is "122:AudioCodes.com:AudioCodes". According to the
RFC, this part is called A1.
● The MD5 algorithm is run on this equation and stored for future usage.
● The result is "a8f17d4b41ab8dab6c95d3c14e34a9e1".
5. The par called A2 needs to be evaluated:
● The method type is "REGISTER".
● Using SIP protocol "sip".
● Proxy IP from ini file is "10.2.2.222".
● The equation to be evaluated is "REGISTER:sip:10.2.2.222".
● The MD5 algorithm is run on this equation and stored for future usage.
● The result is "a9a031cfddcb10d91c8e7b4926086f7e".
6. Final stage:
● A1 result: The nonce from the proxy response is "11432d6bce58ddf02e3b5e1c77c010d2".
● A2 result: The equation to be evaluated is "A1:11432d6bce58ddf02e3b5e1c77c010d2:A2".
● The MD5 algorithm is run on this equation. The outcome of the calculation is the response
needed by the device to register with the Proxy.
● The response is "b9c45d0234a5abf5ddf5c704029b38cf".
At this time, a new REGISTER request is issued with the following response:
REGISTER sip:10.2.2.222 SIP/2.0
Via: SIP/2.0/UDP 10.1.1.200
From: <sip: 122@10.1.1.200>;tag=1c23940
To: <sip: 122@10.1.1.200>
Call-ID: 654982194@10.1.1.200
CSeq: 1 REGISTER
Contact: sip:122@10.1.1.200:
Expires:3600
Authorization: Digest, username: 122,
realm="AudioCodes.com",
nonce="11432d6bce58ddf02e3b5e1c77c010d2",
uri="10.2.2.222",
response="b9c45d0234a5abf5ddf5c704029b38cf"
7. Upon receiving this request and if accepted by the Proxy, the Proxy returns a 200 OK
response, completing the registration transaction:
SIP/2.0 200 OK
Via: SIP/2.0/UDP 10.1.1.200
From: <sip: 122@10.1.1.200>;tag=1c23940
To: <sip: 122@10.1.1.200>
Call-ID: 654982194@10.1.1.200
Cseq: 1 REGISTER
Date: Thu, 26 Jul 2012 09:34:42 GMT
Server: Columbia-SIP-Server/1.17
Content-Length: 0
Mediant 1000 Gateway & E-SBC | User's Manual
- 471 -