Hi I have a grandstream ata(HT701) behind nat which is trying to register to freeswitch with public ip but it is getting 403. Zoiper is working fine with same configuration. These are sip messages after enabling siptrace recv 812 bytes from udp/[x.x.x.x]:5060 at 06:39:06.476367: ------------------------------------------------------------------------ REGISTER sip:y.y.y.y:5070 SIP/2.0 Via: SIP/2.0/UDP 192.168.33.109:5060;branch=z9hG4bK951798483;rport From: "100" <sip:100@y.y.y.y:5070>;tag=1551799885 To: <sip:100@y.y.y.y:5070> Call-ID: 1772924103-5060-2@BJC.BGI.DD.BAJ CSeq: 2012 REGISTER Contact: <sip:100@192.168.33.109:5060

;reg-id=1;+sip.instance="<urn:uuid:00000000-0000-1000-8000-000B829D0E35>" Authorization: Digest username="100", realm="y.y.y.y", nonce="a5163fda-cb35-11e6-bc3a-6bd3c5b5a0c6", uri="sip:y.y.y.y:5070", response="b3e394d5f59e1e3c79cc5ec596d132e1", algorithm=MD5, cnonce="09249246", qop=auth, nc=00000008 Max-Forwards: 70 User-Agent: Grandstream HT701 1.0.8.2 Supported: path Expires: 180 Allow: INVITE, ACK, OPTIONS, CANCEL, BYE, SUBSCRIBE, NOTIFY, INFO, REFER, UPDATE Content-Length: 0

------------------------------------------------------------------------ send 548 bytes to udp/[x.x.x.x]:5060 at 06:39:06.569125: ------------------------------------------------------------------------ SIP/2.0 403 Forbidden Via: SIP/2.0/UDP 192.168.33.109:5060 ;branch=z9hG4bK951798483;rport=5060;received=x.x.x.x From: "100" <sip:100@y.y.y.y:5070>;tag=1551799885 To: <sip:100@y.y.y.y:5070>;tag=0r6HXSrXZD44a Call-ID: 1772924103-5060-2@BJC.BGI.DD.BAJ CSeq: 2012 REGISTER User-Agent: FreeSWITCH-mod_sofia/1.2.14+git~20131019T195513Z~44680b31d9 Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY, PUBLISH, SUBSCRIBE Supported: timer, precondition, path, replaces Content-Length: 0 how can I debug this? thanks