1. It seems, to register to Live Communication server from a SIP client, NTLS or Kerbaros authentication is a must.
How to register from a SIP client which doesn't support NTLS or Kerbaros
Is there any configuration required on LCS to acheive the same
2. If LCS doesn't support HTTP Digest Authentication then its not interoperable with SIP standard rfc 3261 and IMS Please correct me if I am wrong
Please revert back !!!
Best Regards,
Deepak K Bramhapuriya

LCS complience with IMS / SIP standards ?
LOTG
You can license the protocol specs from MS. For information, go here: http://www.microsoft.com/about/legal/intellectualproperty/protocols/mcpp.mspx
There are specs for the MS extensions to SIP as well as NTLM Authentication.
The IETF RFC 4559 on SPNEGO-based Kerberos and NTLM HTTP Authentication in Microsoft Windows may shed some light on NTLM but is not completely germane to SIP.
HTH
Terry
P.S. I'm not a MS employee
mfewtrell
Is there a way to access the SIP NTLM authentication of LCS
It's very hard to develop a client to connect to LCS if we can't find any documentation :(
Thanks
bigove
Per our support engineer:
Regarding following issue, our buddy has 2 questions on SIP standard in LCS.
1) How to register from a SIP client which doesn't support NTLS or Kerberos
2) Does LCS support HTTP Digest Authentication
LCS can choose one of the following based on server settings:
- Kerberos and NTLM (default)
- Kerberos
- NTLM
Communicator (Client) doesn't have UI controls for this - it will simply choose Kerberos if presented - if not, it will select NTLM. If presented with both, it will always choose Kerberos.
Moreover, I don’t think LCS has build-in feature of HTTP Digest Authentication. By default, we only support NTLM and Kerberos authentication.
-brend (ISV Buddy Team)
Jassim Rahma
But I'll try...
Thanks
http200
Is there a way for developers access the SIP NTLM especification
It's very hard to develop a client to connect to LCS if we can't find any documentation.
Thanks