Hi, Not a good idea. Why should I terminate the call just because of some attacker? I want to know if there is any standered defined way to recover from the error condition.
Regards, RadhaKrishna -----Original Message----- From: S B, JAYANTHEESH (JAYANTHEESH)** CTR ** [mailto:[email protected]] Sent: Wednesday, July 14, 2010 4:13 PM To: radhakrishna; 'Rastogi, Vipul (Vipul)'; [email protected] Subject: RE: [Sip-implementors] How sip stack can recover from the followingerror condition..... Hi RadhaKrishna, We can have a retry count [optional configuration parameter] at UAC, once if it reaches to the configured level, we can terminate the session by sending BYE request. Regards, Jayantheesh -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of radhakrishna Sent: Wednesday, July 14, 2010 2:35 PM To: 'Rastogi, Vipul (Vipul)'; [email protected] Subject: Re: [Sip-implementors] How sip stack can recover from the followingerror condition..... Hi, We are already aware that this can be avoided with TLS. But how justified is it to use TLS just for resolving this issue? Thanks for the suggestion anyway. Can any one else provide a solution from a different angle? Regards, RadhaKrishna -----Original Message----- From: Rastogi, Vipul (Vipul) [mailto:[email protected]] Sent: Wednesday, July 14, 2010 2:13 PM To: radhakrishna; [email protected] Subject: RE: [Sip-implementors] How sip stack can recover from the followingerror condition..... To hide SIP headers, there are ways like TLS, SIP/MIME (encapsulation). May be you would like to use TLS in this particular case, which will prevent any attacker to generate accurate UPDATE message. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of radhakrishna Sent: Wednesday, July 14, 2010 14:01 To: [email protected] Subject: [Sip-implementors] How sip stack can recover from the followingerror condition..... Dear All, I want to know if there is any way to come out of the following problem. UAC UAS ----------------------------INV (CSEQ: 1) ------------------------> <---------------------------200 OK---------------------------------- ----------------------------ACK ------------------------------------> Attacker ----------------Update (CSEQ: 10000) ----------> <------------------- 401/407 ------------------------------ -----------------------UPDATE (CSEQ: 2) ------------------> <----------------------- 500 -------------------------------------- Now since the actual UAC is not aware of the attacker, he will keep incrementing the CSEQ every time and will try to send the request. The request would be successful only after trying for some 9999 times. How do we overcome this kind of situation? We suggest that RFC should have a way to convey the CSEQ value stored by UAS in 500 response message so that UAC can come out of the loop. Can anyone please share your opinion on this issue? Regards, RadhaKrishna _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
