News

ECIX’s New Route Server RTT Communities

m385.ecix-rtt-v1

ECIX customers can now make use of brand new Round Trip Time (RTT) communities on the route servers.

Discussions in the German Network Operators Group (DENOG) community have indicated a need to provide path latency information between peers on IX platforms. We have been listening and would like to introduce this new RTT feature for peering customers.

Simply put, ECIX route servers now tag every route with a community which contains the RTT of the peer advertising the route. This enables peers to add the RTT of the advertising peer to their route decision process. The route servers measure the RTT to each peer and take the lowest value measured in 24 hours. Every route received from a peer is then tagged with its RTT. which looks like: (65011:ms)
Note that the route servers tag a value of '99' to anything above 98 ms, and tag a '0' if, for whatever reason, there is no measurement data.

We know that not all BGP implementations allow the user to do logical operations like a higher/lower check on a community. This would mean that peers would need to write 100 different filters; one for each possibility. For this reason, we have included a handy RTT class community which divides the RTT ms into 4 distinct classes:
(65010:0) = unknown
(65010:1) > 0 ms & < 5 ms
(65010:2) > 5 ms & < 20 ms
(65010:3) > 20 ms

We wanted to do more than just advertise these details to our peers. We also wanted to provide a way for peers to tell the route server to either AS-Prepend their routes, or to not send their routes at all, to any peer with an RTT higher or lower than a specific ms. Our new feature includes the following communities which a peer can tag to their own routes:
(65020:ms) do NOT send this route to peers with RTT >= ms
(65021:ms) prepend 1x this route to peers with RTT >= ms
(65022:ms) prepend 2x this route to peers with RTT >= ms
(65023:ms) prepend 3x this route to peers with RTT >= ms

(65030:ms) do NOT send this route to peers with RTT <= ms
(65031:ms) prepend 1x this route to peers with RTT <= ms
(65032:ms) prepend 2x this route to peers with RTT <= ms
(65033:ms) prepend 3x this route to peers with RTT <= ms
Also note that we fully support Large BGP communities [RFC 8092] with all of our ECIX control communities, simply add a '9033' in front of the traditional community: (9033:community:ms).

In addition, ECIX’s new Looking Glass, Alice-LG, can indicate when routes are not being exported to another peer and why. This is useful to check whether or not your no-export communities are working.

Use the RTT communities to write smarter BGP filters.
Use the RTT control communities to influence who gets your routes.
Let us know what you think about this new development.

Stefan Plug