[SR-Users] LCR Modules Comparison

[Henning Westerholt]

On Wednesday 17 August 2011, Spencer Thomason wrote:
> Can anyone shed some light into the differences between the available LCR
> modules?  We have migrated our config from OpenSIPS where we used the
> drouting module to Kamailio where we are using the lcr module.  Our
> ruleset is not crazy huge, about 100k entries.  Are there compelling
> reasons to choose one module over the other?  Is there one that has the
> most active development behind it and is a "standard" for the platform or
> is there one that will be deprecated in the foreseeable future?

Hi Spencer,

the carrierroute module is also actively maintained, mtree as well. The 
drouting is available but probably the one with the least usage here. Its 
initial import has been done from Raul Alexis and I guess they use it in 
production, but don't know details. There were also some patches from other 
people in the last year, but recently it has seen not that much activity.

The modules differ mostly in their provided configuration interface, their 
capabilities and the internal used datastructures IMHO.

lcr
* introduced in 0.9.x times, reworked several times
* provided initially support for a limited number of routes, today it supports 
large route sets as well
* provides easy failover functionaly to try sequentially several gateways
* uses internally a hash table

cr
* introduced in 1.3, reworked for 1.5
* support larger route sets
* provides flexible failure routing capabilities with a dedicated table, but 
is more complicated to setup and use
* uses a trie (tree) internally 

mtree
* introduced in 3.1
* support larger route sets
* provides generic tree matching functionality, but without that much 
additional functionality
* uses a tree internally

drouting
* ported from opensips for 3.0
* support larger route sets
* provides failover capabilities and some special matching as time or date
* uses a trie (tree) internally

Best regards,

Henning