Hello Barry, If I understand you correctly you want to achieve a stable hash algorithm distribution. Right now, I can only think of some bug fixes that could be the reason for the different behaviour of the 4.3.x Kamailio server. I would suggest that you upgrade to a supported version (5.2.x/5.3.x). The carrierroute module also supports a cfg file and can be used to in a somewhat consistent hash mode (you can shift the load of one server to another one without changing the distribution set completely) – if you can’t upgrade right now this might be as well an option for you. Cheers, Henning -- Henning Westerholt – https://skalatan.de/blog/ Kamailio services – https://gilawa.com<https://gilawa.com/> Kamailio Merchandising – https://skalatan.de/merchandising From: sr-users &lt;sr-users-bounces(a)lists.kamailio.org&gt; On Behalf Of Barry Flanagan Sent: Thursday, November 14, 2019 2:01 PM To: SIP Router - Kamailio (OpenSER) and SIP Express Router (SER) - Users Mailing List &lt;sr-users(a)lists.sip-router.org&gt; Subject: [SR-Users] dispatcher, pvar_hash and multiple kamailio instances Hi, I have multiple Kamailio instances using dispatcher using alg “7” - hash over the content of PVs string, both using the same dispatcher list. Is it reasonable to expect both Kamailio, given the same hash_pvar, to select the same host from the same set? Looking at the source I do not see any reason why not, but I am getting different results from the two Kamailio servers. The only difference between them is different minor version numbers - 4.3.4 and 4.3.7 I want to ensure that calls with the same hash_pvar value go to the same backend no matter which Kamailio processes the request. Thanks! -Barry Flanagan