Hi Charles, I tried first to trigger again the bug using some iptables rules (to simulate a network problem) , so Kamailio could not communicate with the memcache anymore:  WARNING: memcached [memcached.c:189]: WARNING: memcached: mcm_server_readable():2582: timeout: select(2) call timed out for read(2)able fds WARNING: memcached [memcached.c:189]: WARNING: memcached: mcm_server_writable():3173: timeout: write select(2) call timed out WARNING: memcached [memcached.c:189]: WARNING: memcached: mcm_server_connect():2290: select(2) failed: select(2) timed out on establishing conn ection NOTICE: memcached [memcached.c:194]: NOTICE: memcached: mcm_server_connect():2297: connect(2) failed NOTICE: memcached [memcached.c:194]: NOTICE: memcached: mcm_server_connect_next_avail():2323: unable to find a server to connect to This looks very much like what i've seen in the logs just before it started to report the "protocol error" problem. But in the simulated case , after I remove the iptables rules that block the access to memcache, Kamailo does not recover from the situation, it just keeps on printing messages like the above, when it should connect to memcache instead. It looks like another libmemcache-related bug to me. Then I tried the same thing with  the latest memcached module from git: With the memcached firewalled after starting Kamailio it prints this to the logs: ERROR: memcached [mcd_var.c:154]: pv_get_mcd_value_helper(): could not get result for  key 29515_HA1 - error was 'SERVER HAS FAILED AND IS DISABLED UNTIL TIMED RETRY' When I flush the firewall rules, it reconnects to memcache, which makes it better than the old one. But how can I be sure that the new one will not have the same "protocol error" issue, since I could not reproduce exactly the problem so far ?  Regards, Dragos ________________________________ From: Charles Chance <charles.chance(a)sipcentric.com> To: Dragos Oancea <droancea(a)yahoo.com>om>; Kamailio (SER) - Users Mailing List <sr-users(a)lists.sip-router.org> Sent: Thursday, June 6, 2013 6:27 PM Subject: Re: [SR-Users] memcache problem - reporting protocol error Hi Dragos, The memcached module has indeed been updated in the master to use libmemcached, as the old libmemcache library is no longer under active development. Have you tried using the latest version of the module from git? Do you still get the same errors? Cheers, Charles On 6 June 2013 16:18, Dragos Oancea <droancea(a)yahoo.com> wrote: Hello www.sipcentric.com Follow us on twitter @sipcentric Sipcentric Ltd. Company registered in England & Wales no. 7365592. Registered office: Unit 10 iBIC, Birmingham Science Park, Holt Court South, Birmingham B7 4EJ.