BCM450 VoIP over AT&T MIS internet circuit

[VoiceOfJoe]

We are upgrading from a BCM400 4.0 to BCM450 5.0 soon and are planning to integrate VoIP phones (1200 series) in a remote office location 3.5hrs away. The present plan is to deploy a new AT&T MIS data circuit with new cisco router, firewall and switch gear. The 16 remote VoIP phones will be connected to this new network infrastructure and connect back to the corporate office initially over a secure Cisco VPN. I'm pricing and sizing 1.5Mbps and 3.0 Mbps circuits. My question is this: Does anyone see a design issue with this approach. The carrier has susggested we go with a MPLS or pt-to-pt circuit for quality of service. What are others running their VoIP over. I'm estimating 32Kbps per VoIP channel or 512Kbps total (1/2 T1, or 25% of 3.0) Seems like we should have sufficient bandwidth for voice traffic. Should we keep Internet traffic off of it and stay with just voice. Otherwise we'll implement split tunneling and use pipe for voice traffic back to corporate along with Internet activity. Would appreciate some feedback from others who have been down the VoIP path already. TIA - VOJ

 

[oldestgeek]

Definitely go with the MPLS or p to p unless T can assure you of QOS on the circuit. The problem isn't bandwidth as much as it is delay and even though the site is 3 hours away, the packets may be routed thousands of miles away. Ordinary Internet traffic on the pipe shouldn't be a problem unless you're streaming video or downloading CAD files, etc. This would of course make QOS on the circuit a must. You should also select a skinny codec (G.729) for those phones at the remote site.

 

[VoiceOfJoe]

Thanks for the input. We'll need to price MPLS and pt-to-pt. Since we don't have MPLS back at our corporate office - are we order (2) MPLS circuits effectively?

VOJ

 

[oldestgeek]

You'll need to order enough circuits to achieve total bandwidth requirements, i.e. if you need3 mips at the branch and 6 at corporate, you'd need to order 2 circuits for the branch and 4 for cor[orate. MPLS can get pretty pricey so you may be better off with a p to p between them.