You could ignore this packet avoiding CPU overload and taking advantage of this packet to keep the nat/firewall open.
Fernando -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Michael Slavitch Sent: Wednesday, February 22, 2006 10:49 PM To: Bill Moats; [email protected] Subject: Re: [Sip-implementors] Packets send to Sip port with only CRLF They are a SIP heartbeat and NAT keepalive. Some NAT bindings are 15 seconds. There is much discussion about standardizing such things in the IETF SIP WG mailing list. M -----Original Message----- From: [EMAIL PROTECTED] on behalf of Bill Moats Sent: Wed 22/02/2006 8:03 PM To: [email protected] Subject: [Sip-implementors] Packets send to Sip port with only CRLF Hello all While testing the compatibility of my SIP implementation with several different end-points, I have discovered some end-points (X-Lite in particular www.xten.com) which periodically send UDP packets to my server's SIP port (5060) which contain only 2 bytes (0x0d 0x0a) CRLF roughly every 10 seconds. According to SIP this constitutes the "empty-line" which separates the headers from the message contents, however there is neither headers nor message contents so the packet has little meaning and my software rejects it as erroneous! Is this operation correct? If so for what purpose would these packets serve and in which RFC is it specified? The only reason I could imagine for this operation is to somehow reset the SIP message framing (which would only be meaningful on TCP not UDP) or maintaining NAT mapping however wouldn't the REGISTER every 60 seconds accomplish this? Could anyone shed some light on this? Thanks in advance Bill Moats _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors -- ----------------------------------------------- This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful. Any views, opinions and content presented in this e-mail are solely those of the author and may not represent those of Objectworld Communications Corp. _______________________________________________ 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
