12-03-2008 06:46 PM - edited 03-18-2019 10:06 PM
Hi, I have troubles with CUPC (7.0) connecting to CUCM (6.1) and passing third-party FW (CheckPoint NGX R65).
CUPC starts SIP connection on UDP:
SRC port: 50000
DST port: 5060
Does anybody know, if it is possible to configure CUPC, that it will start connection from SRC port 5060 too?
CP support claims that SRC port 50000 it is not by RFC SIP standard and they can not easy change FW kernel inspection behaviour. Thank you for all answers,Andrej
12-03-2008 10:07 PM
I am not the SIP expert but I do not think that the CP is correct in this case. It is true that UDP/TCP port 5060 is use for server agent in typical configurations I am not sure that this is required.
RFC 3261 (http://tools.ietf.org/html/rfc3261)
Section 18.2.1
"...It is also RECOMMENDED that a server listen for requests on the default SIP ports (5060 for TCP and UPD, 5061 for TLS over TCP) on all public interfaces...For any port and interface that a server listens on for UDP, it MUST listen on that same port and interface for TCP"
Note the term "recommended". Yes, standard practice is to use 5060 but if one wants to debate compliancy...
In your case, you are using the recommended server listening port. So, no need to debate the finer points. The next question is the client source port. Again, from RFC 3261, section 18.
Paragraph 2: "...When the connection is
accepted by the transport layer, this index is set to the source IP
address, port number, and transport. Note that, because the source
port is often ephemeral, but it cannot be known whether it is
ephemeral or selected through procedures in [4],..."
This specifically states that the client source ports may be ephemeral (>1024 to
You may also want to reference the CUPC release notes:
http://www.cisco.com/en/US/docs/voice_ip_comm/cupc/7_0/english/release/notes/ol15710.html#wp39407
They spell out the port range that CUPC will use for source ports. Note that it is a range of ports that the CUPC client will use. So, if you can convince the security folks to work with you, provide the appropriate range of ports.
Hope this helps.
Regards,
Bill
Please remember to rate helpful responses and identify
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide