Are you intending to use `t_next_contact_flow()` rather than `t_next_contact()`? There's not enough data here to know what your contacts look like. The definition of `t_next_contact_flow()` is:

Function adds a new branch to the request that includes the first contact from contact_flows_avp that matches the +sip.instance value of the flow that has failed.

If your contacts have separate +sip.instance values, then it would be expected that this would fail. Unless you know this to be the case use `t_next_contact()` in a failure route (as opposed to a branch failure route).

Regards, Kaufman

________________________________ From: Benoît Panizzon via sr-users sr-users@lists.kamailio.org Sent: Friday, January 17, 2025 9:15 AM To: sr-users@lists.kamailio.org sr-users@lists.kamailio.org Cc: Benoît Panizzon benoit.panizzon@imp.ch Subject: [SR-Users] Need help with serial branching using: t_load_contacts(1)

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Hi Gang

I guess, I don't completely understand who to properly perform serial branching.

I did try to follow the examples from:

https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.kamail...https://www.kamailio.org/docs/modules/devel/modules/tm.html#tm.f.t_next_contacts

This is, stripped down, the relevant config used.

modparam("tm", "contacts_avp", "tm_contacts") modparam("tm", "contact_flows_avp", "tm_contact_flows")

route[LOCATION] { lookup_to_dset("location", "$var(lookupuri)");

if (!t_load_contacts(1)) { xlog("L_ERR", "$cfg(route): ######### load_contacts failed\n"); sl_send_reply("500", "Server Internal Error - Cannot load contacts"); exit; }

xlog("L_INFO", "$cfg(route): Contacts loaded: $cnt($xavp(tm_contacts))\n");

=> Confirms, there is more than one contact loaded.

if (!t_next_contacts()) { send_reply("480", "Not registered"); }

t_set_fr(5000,1500); # Set 5 second timeout for LAB testing to quickly try the next contact.

t_on_branch("BR_TO_CUST"); t_on_branch_failure("BR_TO_CUST_FAILURE"); exit; }

event_route[tm:branch-failure:BR_TO_CUST_FAILURE] { xlog("BRANCH FAILED $T_reply_code to $rm message\n"); t_on_branch("BR_TO_CUST"); t_on_branch_failure("BR_TO_CUST_FAILURE"); if (t_next_contact_flow()) { xlog("BRANCH FAILED, Try Next\n"); t_relay(); } else { xlog("L_INFO", "No more flows\n"); t_reply("408", "Branch Timeout"); exit; } }

What happens is:

INVITE is sent to the first contact, who is replying RINGING. After 5 seconds the timeout is reached and the branch-failure route engaged.

Jan 17 15:01:15 dev-cpereg01 kamailio[3599432]: ERROR: <script>: BRANCH FAILED 408 to INVITE message Jan 17 15:01:15 dev-cpereg01 kamailio[3599432]: INFO: <script>: No more flows Jan 17 15:01:15 dev-cpereg01 kamailio[3599432]: CRITICAL: tm [tm.c:1554]: ki_t_reply(): w_t_reply entered in unsupported mode

To my understanding, t_next_contact_flow() should have loaded the next ds, but this does not seem to happen.

What am I missing?

-- Mit freundlichen Grüssen

-Benoît Panizzon- @ HomeOffice und normal erreichbar -- I m p r o W a r e A G - Leiter Commerce Kunden ______________________________________________________

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