[Freeswitch-dev] Call to registered phone behind NAT

Oleg Khovayko khovayko at gmail.com
Tue May 25 22:08:35 PDT 2010


I little narrowed problem with NATed client.
There is his registration:

Call-ID:        41f120d4 at
User:           1012 at
Contact:        "user" 
<sip:1012 at;fs_nat=yes;fs_path=sip%3A1012%4091.207.244.1%3A5060>
Agent:          AcctonVoIP/2.5
Status:         Registered(UDP-NAT)(unknown) EXP(2010-05-26 02:45:48)
Host:           olegh.ath.cx
Port:           5060
Auth-User:      1012
Auth-Realm:     olegh.ath.cx
MWI-Account:    1012 at

When he calls me, conversation is OK.

When I (from the local phone) call him (he is so far, and behind NAT), 
ring is OK,
but when he picked up handset -- we both heard nothing.

Looks like FS try to establish connection to IP address, assigned him 
behind his NAT:
FS sends ARP request to resolve this address:

6191 packets received by filter
0 packets dropped by kernel
[root at olegh /usr/local/freeswitch/conf]# tcpdump host '( or'
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on xl0, link-type EN10MB (Ethernet), capture size 96 bytes
00:49:27.911731 IP deskpro.khovayko.com.sip > SIP, 
length: 1339
00:49:28.299781 IP > deskpro.khovayko.com.sip: SIP, 
length: 349
00:49:28.317358 IP > deskpro.khovayko.com.sip: SIP, 
length: 403
00:49:40.420237 IP > deskpro.khovayko.com.sip: SIP, 
length: 829
00:49:40.451060 IP deskpro.khovayko.com.sip > SIP, 
length: 368
00:49:40.691549 arp who-has tell deskpro.khovayko.com
00:49:41.107754 arp who-has tell deskpro.khovayko.com
00:49:42.105717 arp who-has tell deskpro.khovayko.com
00:49:43.107377 arp who-has tell deskpro.khovayko.com
00:49:44.106215 arp who-has tell deskpro.khovayko.com
00:49:45.107216 arp who-has tell deskpro.khovayko.com
00:49:46.105957 arp who-has tell deskpro.khovayko.com
00:49:47.105975 arp who-has tell deskpro.khovayko.com
00:49:48.105804 arp who-has tell deskpro.khovayko.com
00:49:49.107058 arp who-has tell deskpro.khovayko.com
00:49:50.107512 arp who-has tell deskpro.khovayko.com
00:49:50.533533 IP deskpro.khovayko.com.sip > SIP, 
length: 626
00:49:50.794874 IP > deskpro.khovayko.com.sip: SIP, 
length: 355

About SIP trace: I do not know, how to save trace to file from fs_cli.
On the sccreen, there is too many text lines, they very fast gone...

Brian West wrote:
> You don't hav eto do this if you have upnp freeswitch will do this for you even for the media ports... I am not sure what your problem is grab the default config and use it... I know it works if you really do have upnp.
> /b
> On May 24, 2010, at 8:01 PM, Oleg Khovayko wrote:
>> It is behind UPNP, and I forwarded ports 5060-5060 (both TCP+UDP) to server.
>> Also, I have forwarded ports 20000~30000, and for FS setup in the
>> file autoload_configs/switch.conf.xml
>> <param name="rtp-start-port" value="20000"/>  <!-- olegh -->
>> <param name="rtp-end-port"   value="25000"/>

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