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Details on using a C40/60 as conference room telephone. - Possible?

I have several large conference rooms that have Cisco C40/60 installed. I was told that these units could also be used to call across our Cisco Call Manager to place standard phone calls. Is this possible? If so, anyone have some documentation? 


Currently all our Codecs are connected to VCS-Control.






Hi RB,With an ISDN Gateway

Hi RB,

With an ISDN Gateway (or even SIP trunk to a SIP provider), the VCS and a sensible dial plan, you could achieve this without CUCM. Of course, the C series can also be attached to CUCM and you may then get more flexibility, but essentially you would still need to break out to the POTS world somewhere and have in place a dial plan that allows you to do this.

There are potential security implication, but I don't think this is the time for that discussion.




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Ok, awesome. That's some good

Ok, awesome. That's some good info. We do have a SIP trunk from the call manager to the VCS-C currently. However, I don't think it gets used. We do have plans down the road to move all the Cisco codecs to the Call Manager. Is there any documentation that I can read to get a better understanding of what would be required?

What would the potential security implication be? If its a big one then it may not be worth me doing this.


Thanks for your help!


Hey RB,As always, it best to

Hey RB,

As always, it best to read the administration guides for the VCS, CUCM, and (if you are using one) an ISDN gateway.

The security implication that comes to mind is something along the lines of "hair-pinning". A technique whereby external user may be able to place a call directly over you gateway (hence has the potential to run up call charges) through a crafted destination address. Basically a  decent dial plan design would take this into account and such ideas are outlined in the VCS admin guide.

I must say that I am no CUCM expert, but I am guessing the same thing applies here as well.




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