VoIP QoS questions

I am working on an issue as a casual observer (a third party is handling the heavy lifting) and have a few questions.

The issue at hand is moving a business from one phone service provider/ISP to another. The data portion of the migration is pretty straightforward.

The part that a 3rd party is handling is porting the phone numbers and setting up "internal" QoS and "external" QoS.

The part that has me is the internal/external QoS....?

If they are only changing ISPs and nothing else (nothing on the LAN side is getting changed) then why would they worry about setting up QoS on the LAN? From my (inexperienced) point of view, the LAN QoS is already in place and working...why worry about it?

Also, what kind of WAN/external QoS would someone need to setup for a VoIP install? This part is just my general lack of knowledge in this area, I assumed once QoS has been applied on the LAN and the data has been delivered to the demarc no further QoS would be needed...?

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networker050184

For internal it really depends. Is there current QoS set up? How is it set up? Is that compatible with the new phone set up? Matching on IPs rather than markings, etc. may come into play. A lot of factors to investigate. And maybe they just have a preferred template to use that is familiar and supportable by them. Always more than one way to accomplish the same thing.

External QoS I assume they mean on the WAN link, making sure markings are correct etc. QoS on the WAN is usually a much bigger concern than the LAN. On the LAN everything is 10G, probably even bundled, bandwidth to spare everywhere! The WAN on the other hand is a much more oversubscribed model. You don't want your business critical phone conversation sitting in a queue behind Billy's YouTube streaming.

philz1982

Tagging and the like have to match otherwise you will have traffic processing issues. Additionally the provisioning of bandwidth would need to be set right in order to avoid bottlenecks.

--chris--

networker050184 wrote: »

For internal it really depends. Is there current QoS set up? How is it set up? Is that compatible with the new phone set up? Matching on IPs rather than markings, etc. may come into play. A lot of factors to investigate. And maybe they just have a preferred template to use that is familiar and supportable by them. Always more than one way to accomplish the same thing.

Current QoS is setup and works. This is the part that has me puzzled, as you questioned "compatible with new phone set up?" there is no new phone set up. The only thing that is changing is the WAN link. Markings = VoIP specefic term I take it?

networker050184 wrote: »

External QoS I assume they mean on the WAN link, making sure markings are correct etc. QoS on the WAN is usually a much bigger concern than the LAN. On the LAN everything is 10G, probably even bundled, bandwidth to spare everywhere! The WAN on the other hand is a much more oversubscribed model. You don't want your business critical phone conversation sitting in a queue behind Billy's YouTube streaming.

This makes sense, and I never thought of that...

--chris--

philz1982 wrote: »

Tagging and the like have to match otherwise you will have traffic processing issues. Additionally the provisioning of bandwidth would need to be set right in order to avoid bottlenecks.

So is there two types of tagging? LAN and WAN tagging? And this is part of the basic config?

When you say provisioning bandwidth, do you mean both LAN/WAN or just WAN?

chmod

In a typical enterprise scenario you would have the lan QoS part/portion which as someone else mentioned above is not usually a big deal, you might split your network in 2 vlans one for voice and one for data an in a regular 10Gb LAN that should do the trick.

On the other hand, the wan portion would be basically: how you handle the packets reaching the internal interface of the router and leaving on the outside interface, there you can configure how your router prioritize the traffic, define a policy to reserve certain % of the BW for voice traffic, configuring that packets coming from voice vlan have higher priority and are handled first, and that type of stuff.

The rest is up to your ISP.