SIP Question

[Geminorum_cco]

Hi everybody thanks for a great forum.

I wasnt sure where to address this, but here goes

I upgraded an ASA 5505 (this is not a firewall question though) from 8.2(5) to 9.1(4). A leap of faith if you know what i mean hehe. Anyway, they have a CME with (in the 8.2 config) 2 nats one TCP and one UDP to 5060 (SIP). Right, it worked fine untill the upgrade ofcourse.

Now finally i got the voice part working, but only by removing one nat (the UDP). I cleared the xlate table and prepared some traces before i tested with a call to a number in there.

And what i saw kind of confused me a bit because the invite comes in over UDP(5060)... Even though i disabled the NAT statement for that?!

This is propably a silly question but how does that work. How can the invite get through to the CME when the NAT is gone? The other funny part is, if i disable the TCP NAT as well it stops working entirely and all i get is a busy tone!

The when i reenable the TCP NAT i have to wait for a bit before it starts working again.

My thought was that the CME somehow keeps a channel open to the SIP provider, and when

Hope you guys can shed some light over this.

Cheers everybody

[Jon Marshall · Accepted solution]

This thread is a bit difficult to work out where to post but i don't think this forum is the best place as it is neitther a VoIP forum nor a firewall forum.

You say it's not a firewall issue but things are working differently because you upgraded the ASA software so it may be a new behaviour in the firewall that is doing it.

Alternatively there may be some people in the VoIP forums who are working with ASA v9.1 code and have come across this before.

What you could do is pick one of those forums and then in the other one just start a post but simply put a link to the main post and ask for any answers to be added to that one. It may or may not work but if you leave it here it is unlikely anyone will answer.

Not trying to put you off posting i just think you may get better results in one the forums mentioned above.

Jon

[Geminorum_cco]

Hiya Jon

I had the same doubts when i contacted TAC about which technician i needed hehe. No worries, really this is about me not knowing what happens in the crosstalk between the CME and the provider.

I'll see if i can find my way to the voice forum, thanks!

Cheers