an using uc540 i have config cisco ip phones 504 among others and using a dialogic gateway to attribute numbers to the cisco phones they have 5004-5007they number attribution enable calls entering from GSM to reach this phones 5004-5007
but upto now they ring but on the gsm number it doesnt ring and when i capture traffic at the level of the dialgic i see that there is invitefrom dialogic but there is no ack
locally they communicate to together but when calls are coming outside that when it not having ACK.
when call from GSM the cisco phone ringo and shows the GSM number, but on the GSM piece it doesnt Ring and even when the cisco phone user picks up the call there no sign to show that the is on hook
Good, thank you for the nice rating and good luck!
Actually, the trace shows that both devices have private address, and are behind two different NAT routers.
Likely, both non-Cisco NAT routers have no support for SIP ALG, or supports it incorrectly.
So as explained above,. "IP communication" is not enough. There is no "other cause".
You should include the complete trace, as the above is not complete.
However, is seem that the GSM box is on a public IP, while the UC500 is on a private IP behind a NAT and/or firewall router, likely not a Cisco device..
In that case, it's normal that doesn't work. You need to have them both on the same local network.
Otherwise, you will have major problems to make it work.