UC520 Teleworker

[Arthur Kant]

I have a UC520 with two teleworkers in different sites.  All sites connect back to UC520.  Calls between phones and the "Hub" work well but calling between each other is not working.  These are true L2L ipsec tunnels with no mesh.  Do I need to have ip connetivity directly between phones in order for them to work?  I had always thought as long as phone could hit CME the magical world of call delivery would work.

[David Trad]

Hi Arthur,

This might be a silly questions but do you have transcoding in place?

Are you forcing any particular codec on the teleworker phones on the CME side?

Cheers,

David.

[Arthur Kant]

Not a silly question :)  there is no transcoding configured on the system, all G711 to make things simple.  I have this problem now with two clients.  One using traditional CME on ISR and the other with UC500.  Both deployments are setup with a hub and spoke topology.  Static site-to-site (non EZVPN) tunnels back to the head end.  Teleworkers can call great to main office phones.  But the problem is teleworker to teleworker.  Teleworker tunnels are setup to just encrypt data to head end and not between sites (like a DMVPN ..etc / Mesh) so I am thinking this has something to do with it.

[Steven DiStefano]

I wonder if its ACLs on eack teleworker router to allow the subnet of the other?

When you set up a teleworked with CCA, it takes care of TW Router and UC500, but it doesnt know about the others, maybe?  Not sure.  Thinking out loud I guess...

[Arthur Kant]

I can confirm that they do not have acl's for the other "spoke" subnet.  So the big question is: On a CME system must all individual SCCP phones have IP access each other in order to make successful calls or can you hairpin RTP ..etc for voice through the router.

[Steven DiStefano]

Your right.  I was confused with data VLAN for a moment.   A registered phone on the host UC500 should be enough for call control.