3.
According to the sub-header present in the WWW-Authenticate header the correct
REGISTER request is formed.
4.
Since the algorithm used is MD5, then:
•
The username is equal to the endpoint phone number: 122
•
The realm return by the proxy: audiocodes.com
•
The password from the ini file: AudioCodes.
•
The equation to be evaluated: (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: 'REGISTER:sip:10.2.2.222'.
•
The MD5 algorithm is run on this equation and stored for future usage.
•
The result is:'a9a031cfddcb10d91c8e7b4926086f7e'
6.
The 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 gateway to register with the Proxy.
•
The response is: 'b9c45d0234a5abf5ddf5c704029b38cf'
At this time a new REGISTER request is issued with the 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/Mediant 1000/v.4.20.299.410
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"
SIP User's Manual
410
Mediant 1000
Document #: LTRT-83302