Sip-ua can't send public address

[g.disabatino]

I have a 827-4v that have a ADSL modem broke.I have a 837 that are a gateway of my network.The problem is that a sip-ua agent send a private IP of 827-4v for authenticate whit an external SIP server...like this :

CSeq: 3698 REGISTER

Contact: <sip:0861XXXXS@192.168.1.5:5060>

Expires: 3600

the sip-ua are configure in this mode :

authentication username 08611XXXX password XXXXXX

nat symmetric role passive

nat symmetric check-media-src

aaa username proxy-auth

retry invite 4

retry response 3

retry bye 2

retry cancel 2

registrar dns:voip.eutelia.it:5061 expires 3600

sip-server dns:voip.eutelia.it:5061

The 837 gateway router have a static NAT like this :

ip nat inside source static udp 192.168.1.5 5061 interface Dialer0 5061

ip nat inside source static udp 192.168.1.5 5060 interface Dialer0 5060

I have read every thing about a SIP NAT etc but I do know what I have to do!!!

[hadbou]

sip:0861XXXXS@192.168.1.5:5060 was what was sent, however this is not a valid SIP address as SIP addresses are supposed to be in the form of user@host. Because it is an invalid address the phone most likely reuses the previous

contact info.

[g.disabatino]

Thank you but I know and I write this!

The problem for me is a configuration of the 837 (the gateway of my network) for SIP transparent NAT.

This for give a chance at a 827-4v to keep a valid pubblic addres to send in authentication.

[paolo bevilacqua]

Which IOS do you have on the 837?

Do you have access to IOS downloads to upgrade to latest image ?

It should replace the private address with the public one.

[g.disabatino]

The IOS is c837-k9o3sy6-mz.124-5b.bin

I have a smartnet for upgrade the latest IOS image.

I have just 1 pubblic address and is for 837.

The solution will be this ? : http://www.cisco.com/en/US/products/ps6441/products_configuration_guide_chapter09186a008071c4ba.html#wp1066574

the " Hosted NAT Traversal for Session Border Controller " .

If yes I can try to upgrade my flash and download the c837-k9o3sy6-mz.124-15.T1.bin IOS flash image that have this feature.

If not....I don't know what I have to do...may be use the 837 like a modem for 827-4V ?