Hello, you are instructing the uac module to use dialog to store the data: https://kamailio.org/docs/modules/devel/modules/uac.html#uac.p.restore_dlg In this case you should not see the vsf/vst information in the SIP message. It might be in some cases that your dialogs are not tracked correctly, and then the uac module might not be able to use this for storage. Cheers, Henning -- Henning Westerholt – https://skalatan.de/blog/ Kamailio services – https://gilawa.com *From:* sr-users &lt;sr-users-bounces(a)lists.kamailio.org&gt; *On Behalf Of *David Escartín *Sent:* Tuesday, June 15, 2021 7:51 AM *To:* Kamailio (SER) - Users Mailing List &lt;sr-users(a)lists.kamailio.org&gt; *Subject:* [SR-Users] vsf/vst question Hello all! as we knew vsf/vst were added to the RR header when using uac_replace for From/To headers. BUt we observed that some versions ago (we are using now 5.4) that stop happening with this setup modparam("uac", "restore_mode", "auto") modparam("uac", "restore_dlg", 1) modparam("rr", "enable_full_lr", 0) modparam("rr", "enable_double_rr", 1) modparam("rr", "append_fromtag", 1) and only ftag, did are added as param to RR However we have seen that when using multihomed kamailio instance and doing uac_replace, vsf/vst are included also with ftag and did params. Is that behaviour known or expected? thanks a lot and regards david -- <http://www.sonoc.io/> David Escartín NOC engineer *www.sonoc.io* <http://www.sonoc.io/> [image: LinkedIn] <https://www.linkedin.com/company/sonoc> [image: Twitter] <https://twitter.com/sonoc_> [image: Facebook] <https://www.facebook.com/SONOCio/> This e-mail is for the exclusive use of its recipients and may contain business secrets or other confidential or privileged information. Any unauthorised use, copying, publication or distribution of this e-mail is strictly prohibited. If you are not the intended recipient, please inform us immediately by replying to this e-mail and delete it, including any attachments or copies on your system. In accordance with the GDPR (EU) 2016/679 and the LOPDGDD 3/2018, we inform you that this e-mail address and/or any other personal data you have provided us with will be treated by SONOC with absolute confidentiality and with the only purpose of providing you with the requested services, due to your condition as a client, supplier or because you have requested information from us at any time. These data will only be kept for as long as required to comply with legal obligations. You can exercise your rights at any time by sending an e-mail to: *dataprotection(a)sonoc.io* &lt;dataprotection(a)sonoc.io&gt;*.* &lt;dataprotection(a)sonoc.io&gt;