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SCCP Call flow

We are testing some 8941's through a VPN connection.  My tester in the remote location has been testing by calling 2 phones in his office.  Is this a valid test of a Video Call through a VPN connection?  Does call manager hand the acutal call off to the phones so that the actual call is not going over the VPN.  There is no voice gateway at this site, just 5 phones setting behind an ASA firewall.

Let me know if you need more information and thanks again for the help!

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VIP Super Bronze

SCCP Call flow

The signalling (sccp) will go via the VPN on port 2000, however rtp stream will flow directly between the ip phones, hence it will bypass the VPN

Please rate all useful posts "The essence of christianity is not the enthronement but the obliteration of self --William Barclay"
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SCCP Call flow

CallManager won't know or care if phones are on a localy routed subnet, or connected via a VPN from the otherside of the solar system. The only thing that will care will be the phone, as it will have to initially setup the VPN connection. But after that, it'll use it as if wasn't there and carry on as normal.

GTG

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VIP Super Bronze

SCCP Call flow

The signalling (sccp) will go via the VPN on port 2000, however rtp stream will flow directly between the ip phones, hence it will bypass the VPN

Please rate all useful posts "The essence of christianity is not the enthronement but the obliteration of self --William Barclay"

SCCP Call flow

aokanlawon wrote:

...rtp stream will flow directly between the ip phones, hence it will bypass the VPN

I've used phone VPN on 7945, 7965, 9971s, and the media has always gone via the VPN. Yes, this can lead to tromboning, but there's no easy way round that without a cleverer (i.e more complex) VPN client on the phone.

I know there have been issues with what happens about non-voice phone generated traffic (e.g. Services/Directories HTTP requests).

GTG

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VIP Super Bronze

SCCP Call flow

Gordon,

The assumption is that phones are located in the office. But looking at the post again, it looks like there as a phone across the VPN. In this case yes calls will go via the VPN.

Please rate all useful posts "The essence of christianity is not the enthronement but the obliteration of self --William Barclay"
Community Member

SCCP Call flow

Thanks all!

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