### Description This issue has already been reported in the past both on GitHub ( Issue #2659 ) and on the [mailing list](https://lists.kamailio.org/pipermail/sr-users/2022-April/114620.html). We are experiencing some issues with UPDATE messages being sent by the PSTN after an early media announcement. To reproduce the issue we can call a specific number that has an early media announcement, since it's a paid phone number it has to announce how much it would cost before picking up the call. In this initial part the call is being negotiated in g711a. As soon as the announcement ends, the PSTN sends an UPDATE message containing the new desired codec (g729) for the actual call. Kamailio doesn't route the UPDATE message to the destination and it instead replies with a 404 message. If topos is disabled the update message gets routed correctly. #### SIP Traffic I've attached a pcap with anonymized IPs to make it harder for bots. Here is a legend for the IPs: - 12.34.123.123 is Kamailio - 62.23.19.74 is the PSTN - 1.2.130.40 is the client making the call [errorupdate_anon.zip](https://github.com/kamailio/kamailio/files/8522365/er… ### Additional Information * **Kamailio Version** - output of `kamailio -v` ``` version: kamailio 5.5.4 (x86_64/linux) flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLOCKLIST, HAVE_RESOLV_RES, TLS_PTHREAD_MUTEX_SHARED ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: unknown compiled with gcc 10.2.1 ``` * **Operating System**: ``` Linux 5.10.0-13-amd64 #1 SMP Debian 5.10.106-1 (2022-03-17) x86_64 GNU/Linux ``` -- Reply to this email directly or view it on GitHub: https://github.com/kamailio/kamailio/issues/3090 You are receiving this because you are subscribed to this thread. Message ID: <kamailio/kamailio/issues/3090(a)github.com>