optimizing MPLS network

[vortmax]

We have an MPLS network with several remote nodes that route back to a headend network. This network provides internet traffic for approx 100 users on each node.

The main router is connected to the MPLS cloud via a 6 Meg pipe (moving up to a 10 Meg shortly) and each remote node is linked to the MPLS cloud via a 3 or 6 Meg pipe depending on the size of the site.

The MPLS network serves two networks to each node. We have one main network which servers as a backbone for all of the servers to talk, including relaying DHCP traffic from the remote nodes back to the headend and tftp traffic from the headend to the sites (so latency is a concern). The other subnet is for internet traffic, which is routed straight out to the gateway, keeping it from accessing the support servers. We run QOS on the network giving the first subnet realtime priority, then common internet traffic on the second subnet, followed by everything else.

So in short we have:

subnet A: COS 1
subnet B- port 80,443,ect..: COS 2
subnet B- everything else: COS 3

We are looking for a way to optimize the traffic flowing across the mpls network as much as possible to squeeze every bit out of the circuits, as adding an extra 1.5 Mbit (another bonded T-1) is really costly. I've looked at products like the fatpipe Kompressor, which is a packet compressor, but it is designed to work across a WAN link and not a LAN segment and the encapsulation negates the QOS.

My firewall/default gateway is a DL360 with dual pentium 4's and 2 gig of ram running linux, so I have plenty of spare cycles and memory. Right now the QOS does a fantastic job of shaping traffic and handling high loads, but latency is still a bit of an issue.

Is there any sort of compression or optimization I can implement on the incoming packets to increase my throughput or at least drop my latency? Most of the traffic is standard port 80 web traffic, but there is a fair amount of P2P and we have quite a few users who use VOIP and play online games who would benefit from a lower latency link. I don't currently have another server on the other end of the MPLS cloud, but it wouldn't be hard to implement that if I needed something to run decompression.

 

[rjfoster]

You're running multi-megabit connections with MPLS divided into 3 classes and you're concerned about latency for P2P sharing, online gamers, and VoIP (I'm assuming this isn't business VoIP, either)?

I hate to break the news to you, but you have to pick something to be a priority.

Any WAN/link optimizer (packet compression, caching, etc) is only going to increase latency. However, there are a few things that come to mind:

1) you may be able to use WAN optimizer on web-only traffic. How much of a benefit you'll get depends on what percentage of traffic is web traffic. But typical http traffic can be cut to a quarter or more (I've seen as high at 90%). But if you're trying to improve the experience of web-based gaming, then this might not be a good solution.

2) Analyze your COS1 traffic. Chances are, not all of that needs to be COS1. There's a lot of server chatter and other things (email, for example) that no one will ever notice if latency goes from 50ms to 150ms.

Good luck.