Voice over IPSec Site-to-Site VPN

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Jun 16th, 2007
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We would like to establish Voice connectivity to reduce calling cost between our two offices.

We have dedicated internet lease line of 512kbps, which we would like to use for internet, voice

I would appreciate your feedback about feasibility of this solution and experience to share.


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dominic.caron Tue, 06/19/2007 - 10:26
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with QOS, you can control the outbound trafic in both site to give a prio to voice. The problem is when the Internet traffic mix with the inter-site traffic and the ISP start dropping frame at random.

If it's the same ISP in both side and you can get them to pass voice before dropping traffic, your solution will work relatively well.

ealves-crhc Tue, 06/19/2007 - 12:49
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I have created a remote site to main site IPSec/GRE-VPN Tunnel and connected Cisco 7940 phones to a Call Manager and ICD extension to an IPCC server for our remote call center agents.

The only issues I ran into thus far is that I am having an issue getting VoIP Monitoring working for the remote agent

Products used in our test case feasibility study are

Cisco 871 with Advanced IP software

Cisco c79xx phones

IPCC Express 3.1 (2)

CCM 3.5

Cat 3560


Cisco 3725

srue Thu, 06/21/2007 - 06:27
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make sure you enable G729 for the remote location. if you are using a VPN device which supports QoS, make sure you enable that properly as well.


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