Dear friends After spending few days converting my app to PJSIP, today I had to roll back the upgrade because in the SDP, the Owner section is wrong, or I misconfigured something This is what my client said: "That OK message from 1.1.1.1 can not be parsed by our switch due to address representation in their SDP: Owner/Creator, Session Id (o): Pitcom 2723451647 2723451649 IN IP4 Pitcomlxc Such address representation not supported, there should be IP address instead of domain name. Example: Owner/Creator, Session Id (o): Pitcom 2723451647 2723451649 IN IP4 1.1.1.1 In fact, I traced it in the SDP packet, I see o=Pitcom 3991413436 3 IN IP4 pitcomlxc where pitcomlxc is the host name. How do I make PJSIP use an IP address there instead of the host name? My /etc/hosts.com has an entry for pitcomlxc, but it makes no difference.