Hi, I would like to have my SIP clients authenticate with Active Directory (AD). I am using RADIUS in the middle to do the digest based authentication between by sip client and AD. SIP Client ---> RADIUS Client ---> RADIUS Server (IAS of windows server) ----> Activer Directory is my setup. I downloaded RADIUS Client version 1.1.6 (which is the latest i find in freeradius.org) to do the digest based Auth. Following is the AV pair i used to form my Request packet, as per RFC 4590/5090 PW_USER_NAME PW_SERVICE_TYPE PW_DIGEST_REALM PW_DIGEST_METHOD PW_DIGEST_ALGORITHM PW_DIGEST_URI RADIUS server (IAS of Windows) complains of malformed packets. If any of you have used digest based authentication, using Freeradius client, i would like you to help me with this. Also, i am not sure how to add message autehnticator to this request message, which i understand is mandatory. Not sure if this is THE issue. Thanks Varad Windows Live Messenger. Multitasking at its finest. _________________________________________________________________ Twice the fun—Share photos while you chat with Windows Live Messenger. http://www.microsoft.com/india/windows/windowslive/messenger.aspx