Hi, I am using openser 1.2.3. Router is PATTON 4960. I am using domain name to send calls to openser. First invite comes to openser & openser sends 407 to the router & then getting ACK from the router to openser. Now the invite with authentication comes after almost 10 to 11 sec Since ACK comes to openser. Here is the trace: # U 2008/12/19 12:24:24.374228 XXX.XXX.XXX.XXX:5060 -> YYY.YYY.YYY.YYY:5060 INVITE sip:[TO_NUMBER]@[EMAIL PROTECTED] SIP/2.0. Via: SIP/2.0/UDP XXX.XXX.XXX.XXX:5060;branch=z9hG4bK227032cab. Max-Forwards: 70. Content-Length: 341. To: sip:[TO_NUMBER]@[EMAIL PROTECTED]. From: sip:[FROM_NUMBER]@[EMAIL PROTECTED];tag=72a0c76ae3d477c. ... # U 2008/12/19 12:24:24.374544 YYY.YYY.YYY.YYY:5060 -> XXX.XXX.XXX.XXX:5060 SIP/2.0 407 Proxy Authentication Required. Via: SIP/2.0/UDP XXX.XXX.XXX.XXX:5060;branch=z9hG4bK227032cab;rport=5060. To: sip:[TO_NUMBER]@[EMAIL PROTECTED];tag=b802e73ab92fec121a4f880263d541a3.7575. From: sip:[FROM_NUMBER]@[EMAIL PROTECTED];tag=72a0c76ae3d477c. ... # U 2008/12/19 12:24:24.407646 XXX.XXX.XXX.XXX:5060 -> YYY.YYY.YYY.YYY:5060 ACK sip:[TO_NUMBER]@[EMAIL PROTECTED] SIP/2.0. Via: SIP/2.0/UDP XXX.XXX.XXX.XXX:5060;branch=z9hG4bK227032cab. Max-Forwards: 70. Content-Length: 0. To: sip:[TO_NUMBER]@[EMAIL PROTECTED];tag=b802e73ab92fec121a4f880263d541a3.7575. Route: <sip:[EMAIL PROTECTED]:5060;lr>. .... # U 2008/12/19 12:24:35.667448 XXX.XXX.XXX.XXX:5060 -> YYY.YYY.YYY.YYY:5060 INVITE sip:[TO_NUMBER]@[EMAIL PROTECTED] SIP/2.0. Via: SIP/2.0/UDP XXX.XXX.XXX.XXX:5060;branch=z9hG4bK3362d177f. Max-Forwards: 70. Content-Length: 341. To: sip:[TO_NUMBER]@[EMAIL PROTECTED]. From: sip:[FROM_NUMBER]@[EMAIL PROTECTED];tag=72a0c76ae3d477c. Route: <sip:[EMAIL PROTECTED]:5060;lr>. ... U 2008/12/19 12:24:35.692576 YYY.YYY.YYY.YYY:5060 -> ZZZ.ZZZ.ZZZ.ZZZ:5060 INVITE sip:[TO_NUMBER]@ZZZ.ZZZ.ZZZ.ZZZ:5060;transport=udp SIP/2.0. Record-Route: <sip:[TO_NUMBER]@[EMAIL PROTECTED]:5060;ftag=72a0c76ae3d477c;lr=on>. Via: SIP/2.0/UDP YYY.YYY.YYY.YYY;branch=z9hG4bK32dd.6cc062c5.0. Via: SIP/2.0/UDP XXX.XXX.XXX.XXX:5060;rport=5060;branch=z9hG4bK3362d177f. Max-Forwards: 69. Content-Length: 341. To: sip:[TO_NUMBER]@[EMAIL PROTECTED]. From: sip:[FROM_NUMBER]@[EMAIL PROTECTED];tag=72a0c76ae3d477c. ... U 2008/12/19 12:24:35.731432 ZZZ.ZZZ.ZZZ.ZZZ:5060 -> YYY.YYY.YYY.YYY:5060 SIP/2.0 100 Trying. Call-ID: 1c00f084ccd0232ad5ab638dc6a7ccfd@[EMAIL PROTECTED]. CSeq: 1965370819 INVITE. From: sip:[FROM_NUMBER]@[EMAIL PROTECTED];tag=72a0c76ae3d477c. .... U 2008/12/19 12:24:35.849714 ZZZ.ZZZ.ZZZ.ZZZ:5060 -> YYY.YYY.YYY.YYY:5060 SIP/2.0 183 Session Progress. Call-ID: 1c00f084ccd0232ad5ab638dc6a7ccfd@[EMAIL PROTECTED]. CSeq: 1965370819 INVITE. From: sip:[FROM_NUMBER]@[EMAIL PROTECTED];tag=72a0c76ae3d477c. To: sip:[TO_NUMBER]@[EMAIL PROTECTED];tag=86f125f633683d0. ... # U 2008/12/19 12:24:35.849961 YYY.YYY.YYY.YYY:5060 -> XXX.XXX.XXX.XXX:5060 SIP/2.0 183 Session Progress. Call-ID: 1c00f084ccd0232ad5ab638dc6a7ccfd@[EMAIL PROTECTED]. CSeq: 1965370819 INVITE. From: sip:[FROM_NUMBER]@[EMAIL PROTECTED];tag=72a0c76ae3d477c. To: sip:[TO_NUMBER]@[EMAIL PROTECTED];tag=86f125f633683d0. Can anybody help me to trobleshoot the issue? Thanks in Advance!! -- Krunal patel