How does my DX80 resolve a sip address?

[sam.christiansen1]

My DX80 (software ce 9.0.0) is able to resolve a sip address (vmr@domain.com) without any registrar but can't dial an IP address (vmrnumber@ipaddress) when using any sip registration (even though the vmrnumber@ipaddress is sip routable and can be dialled when unregistered). We have a number of Polycom Group systems in our environment as well that can resolve these IP addresses but can't resolve the SIP address unless using a registrar. 

Can someone point me in the right direction of what's happening here? Do cisco systems handle SIP calls differently than polycom units? Does a VC system just need dns in order to resolve SIP?

[Wayne DeNardi]

A lot of it will depend on how your DX is configured and what call control platform it is using.

Just because the address looks like a SIP URI, it doesn't mean that it is.  The H.323 Annex O addresses use the same format.  Is your DX perhaps configured as an H.323 endpoint, and not SIP?

Wayne
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[sam.christiansen1]

Hi Wayne,

Nothing configured under h.323. I guess my main concern is how is it able to resolve a sip vmr@domain.com address when not registered to anything? I'm just not sure how it manages to resolve the address without any registrar and why most other vendor endpoints are incapable of doing this. 

[Joe Vallender]

Probably using a DNS server to resolve the @domain.com.

[sam.christiansen1]

That's what i'm suspecting ( i don't know how else it possibly could) but then other vendors are incapable of properly dialling this address (they can ping and resolve it and even connect via h.323 but can't get a sip call to initiate) and I'm curious why the cisco unit is capable of doing it without issue

[Patrick Sparkman · Accepted solution]

If the endpoint isn't registered to a call control server such as CUCM or VCS, it will perform a DNS lookup to try and resolve the domain.  It sounds as if your DX80 is configured as a standalone endpoint, in which case you should use H323, see Vivek's post in sx20-standalone for the required configuration and firewall ports.

[sam.christiansen1]

thank you guys for info!