Performance Routing Advice

[Patrick McHenry]

Hi,

For our main site and each remote site we have an MPLS circuit on one router plus an Internet circuit with a VPN tunnel for backup on a different router. I was wondering if there was a way to create performance metrics with an IP SLA and have the routers dynamically choose which is the best circuit for a given time/type of traffic.

For example; if the IP SLA reports a threshold of jitter through the MPLS connection could the router then pass voice traffic though the VPN connection?

I want to start looking into this. I've looked at some docs for PIRO and PFR. Just want to get some advice on how I should go about doing this before I really dig into it.

Thank you, Pat

[Dragan Ilic]

Well PfR (previosly OeR) is just builded for that purpose...so I think you are on good track.

First check if your routers and licenses support that 

BR,

Dragan

[Patrick McHenry]

Thanks for the response - I wasn't able to give you a rating though - maybe they are still trying to work out the new site changes?

Regardless, correct me if I'm wrong but isn't PIRO the new PFR?

Also, can you point me in the right direction to learn about this? Good docs you know of?

Thank you

[Dragan Ilic]

No PIRO is not an new PfR - it only extend functionalities of PfR in some way. Official cisco.com:

Protocol Independent Route Optimization (PIRO)

The PfR - Protocol Independent Route Optimization (PIRO) feature was introduced to extend the ability of PfR to identify and control traffic classes. Prior to PIRO, PfR optimizes paths for traffic classes that have a parent route--an exact matching route, or a less specific route--in BGP or static route databases. PIRO enables PfR to search the IP Routing Information Base (RIB) for a parent route allowing PfR to be deployed in any IP-routed environment including Interior Gateway Protocols (IGPs) such as OSPF and IS-IS.

The search for a parent route starts in the BGP routing database and, if no parent route is found, the static route database is searched. If a parent route is still not located, the RIB is searched. When a match is found after a parent route search of the RIB, route control is applied to the traffic class using policy-based routing (PBR) where a dynamic route map is created.

After PfR route control mode is enabled, no new customer configuration is required to enable PIRO.

On the master controller the show pfr master prefix command will display PIRO routes as “RIB-PBR” in the output.

Regarding new materials for you to learn from - well there is really many examples on internet with this kind of solutions and off course cisco.com as No 1 source. So just try with terms which we discussed already...oh and please check more on Cisco Intelligent WAN solution - there you will see some real implementation of PfR (along with WAAS, DMVPN etc)... Cisco IWAN...

BR,

Dragan

[Joseph W. Doherty]

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Posting

As Dragan has posted, PfR might very well serve your needs, and its PIRO enhancement, just allows it to works with any routing protocol (originally it only supported statics and BGP).

The Cisco configuration guides and whitepapers are probably your best sources for PfR information.  I don't know whether anyone has published a book on using PfR, you might search the Internet.

In principle, you would configure PfR for active monitoring.  PfR will then run its own IP SLA tests.  You also need to define your traffic into QoS classes, which I believe, PfR can then provide different levels of desired performance, as part of its criteria whether a flow needs to be moved, especially relative to another.

I had done much with the earlier version of PfR, OER, but that version didn't support performance levels per class.  So, unfortunately, off-the-top-of-my-head, I'm unable to provide examples of "how to".