CISCO SIP

[Don Russell]

David Timms wrote:
> tony.chamberlain at lemko.com wrote:
>> This may be outside the scope of this list, but maybe someone will
> ...
>> i figure as long as I cannot ping the SIP phone from a different
>> network, through the router, the SIP phone will not be able to reach
>> the proxy machine, A.B.C.D.
>>
>> Any suggestions how I might make that IP address (W.X.Y.Z) available
>> to the outside world?
> If all parties are routed, then you should have no problem. But if you 
> are using a firewall/NAT, then the firewall has to know about the SIP 
> protocol {ie application layer gateway}, so that it can track and 
> proxy the extra connections that are formed between the devices.
>
> DaveT.
>
I Dave T's comments are relevant and you use Cisco IOS as your firewall, 
depending on the IOS version, you can add sip-awareness to it...

On your router, in "enable mode":
conf t
ip inspect name (firewallname) sip

you may also use sip-tls


Cheers