[OpenSIPS-Users] Strange errors forwarding requests

[Erik Versaevel]

Hi all,

I'm building a setup in which opensips is acting as registar for my endpoints and loadbalancing
calls made by those endpoint over an cluster of asterisk machines. (so that if we need more asterisk
power, we just have to add another destination to the loadbalancer module)
Opensips is listening on multiple IP addresses and uses the loadbalancer module to poll my asterisk
machines and select the destination.
My problem is that every now and then opensips fails to forward an invite to my asterisk cluster and
generates

	"ERROR:core:udp_send: sendto(sock,0x77b81280,1353,0,0x77b81b04,16): Operation not permitted(1)"

there is some iptables filtering on this machine, however it is not showing drops in the logfile (and it keeps
occuring even without any iptable rules).
I tried stracing opensips but all i get is:

	opensipstrace.7423:sendto(6, "INVITE sip:E164_DST_PHONE_NR at OPENSIPS_IP_ADDRESS SIP/2.0
	Record-Route: <sip:OPENSIPS_IP_ADDRESS;lr=on;ftag=AI05ED431A05432EB8;nat=yes;did=fd6.e1f16fe3;vsf=AAAAAAMIBgl3AggLFgF5HAAFGhwBHzE3NC44MQ-->
	Via: SIP/2.0/UDP OPENSIPS_IP_ADDRESS;branch=z9hG4bK3177.1e0e38b7.0
	Via: SIP/2.0/UDP 192.168.178.44:5060;received=CPE_IP_ADDRESS;rport=61008;branch=z9hG4bK2010Apr222938466E164_DST_PHONE_NR
	To: <sip:E164_DST_PHONE_NR at OPENSIPS_IP_ADDRESS>
	From: \"3961\" <sip:3961 at OPENSIPS_IP_ADDRESS>;tag=AI05ED431A05432EB8
	Call-ID: AIF001C45E85F7921C at 192.168.178.44
	CSeq: 2 INVITE
	Max-Forwards: 69
	Contact: <sip:E164PHONE_NR at CPE_IP_ADDRESS:61008;line=AIF8F01E8DF866D7CB>
	Accept: application/sdp
	Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER
	Allow-Events: dialog,message-summary
	P-Preferred-Identity: <sip:E164PHONE_NR at OPENSIPS_IP_ADDRESS>
	Privacy: none
	User-Agent: SomeStrangeDude
	Content-Type: application/sdp
	Content-Length: 324
	I-FromDisp: <null>
	I-FromUri: E164PHONE_NR
	I-CustId: 3961
	
	v=0
	o=intelligate 1133701155 1133701155 IN IP4 192.168.178.44
	s=call
	c=IN IP4 CPE_IP_ADDRESS
	t=0 0
	m=audio 5004 RTP/AVP 18 8 101
	a=rtpmap:18 G729/8000
	a=fmtp:18 annexb=no
	a=rtpmap:8 PCMA/8000
	a=rtpmap:101 telephone-event/8000
	a=fmtp:101 0-15
	a=sendrecv
	a=ptime:20
	a=direction:active
	a=oldmediaip:192.168.178.44
	", 1253, 0, {sa_family=AF_INET, sin_port=htons(5060), sin_addr=inet_addr("ASTERISK_IP_ADDRESS")}, 16) = -1 EPERM (Operation not permitted)

I also use the uac_replace_from() to mangle the from header so asterisk uses the correct user/peer/client to connect the call (codec/dialplan etc).
I'm having trouble reproducing the error as it's not allways occuring, the errors i straced where mainly the initial invite towards my asterisk
cluster and a few 200 OK's which didn't get processed correctly.

Any clues on how to debug this further?

Kind regards,

Erik Versaevel