SIP User's Manual 272 Document #: LTRT-65415
MediaPack Series
3. According to the sub-header present in the WWW-Authenticate header, the correct
REGISTER request is created.
4. Since the algorithm is MD5:
• The username is equal to the endpoint phone number 122.
• The realm return by the proxy is audiocodes.com.
• The password from the ini file is AudioCodes.
• The equation to be evaluated is (according to RFC this part is called A1)
‘122:audiocodes.com:AudioCodes’.
• The MD5 algorithm is run on this equation and stored for future usage.
• The result is ‘a8f17d4b41ab8dab6c95d3c14e34a9e1’.
5. Next, 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:
• The A1 result: The nonce from the proxy response is
‘11432d6bce58ddf02e3b5e1c77c010d2’.
• The 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
Server: Audiocodes-Sip-Gateway/MediaPack/v.6.00.010.006
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”