I have an issue which I’m not sure I can do anything about. I am using a Foundry Server Iron 4G device to perform SIP loadbalancing of our inbound calls. I currently have 4 asterisk servers sitting behind the load balancer. The problem I am running into has to do with the healthcheck foundry is performing to verify the server is up and running. It uses a REGISTER request to confirm the system is up.
What it expects is a REGISTER followed immediately by a “200 OK”. What it gets from Asterisk is first a “100 Trying” followed by a “200 OK”. Basically it sees the middle packet and immediately ‘fails’ the server. Do I have an options here? Currently I have have health checks disabled, but that isn’t a good long term solution.
FROM FOUNDRY DOCS - EXPECTED BEHAIVOR:
Request: REGISTER sip:companyname.com SIP/2.0
Via: SIP/2.0/UDP 172.16.1.2:1034;branch=z9hG4bKh123456
Max_Forwards: 70
To: <sip: dummy-user@companyname.com >
From: Server Iron <sip: dummy-user@companyname.com>; tag=123456
Call-ID: 25875172.16.1.155@172.16.1.2
CSeq: 101 REGISTER
Contact: sip:172.16.1.2 Expires: 0 Content-Length: 0
Response: SIP/2.0 200 OK.
Via: SIP/2.0/UDP 172.16.1.2:1034;branch=z9hG4bKh123456
Max_Forwards: 70
To: sip:dummy-user@companyname.com;tag=118429
From: Server Iron sip:dummy-user@companyname.com
Call-ID: 25875172.16.1.155@172.16.1.2
CSeq: 101 REGISTER
ACTUAL INTERACTION OF SYSTEMS
<— SIP read from 10.2.1.13:1046 —>
REGISTER sip:10.2.252.181 SIP/2.0
Via: SIP/2.0/UDP 10.2.1.13:1046;branch=z9hG4bK16862
Max-Forwards: 70
To: Server Iron sip:healthcheck@10.2.252.181
From: Server Iron sip:healthcheck@10.2.252.181; tag=14333
Call-ID: 527910.2.252.181@10.2.1.13
CSeq: 2105 REGISTER
Contact: sip:10.2.1.13
Expires: 0
Content-Length: 0
<— Transmitting (no NAT) to 10.2.1.13:1046 —>
SIP/2.0 100 Trying
Via: SIP/2.0/UDP 10.2.1.13:1046;branch=z9hG4bK16862;received=10.2.1.13
From: Server Iron sip:healthcheck@10.2.252.181; tag=14333
To: Server Iron sip:healthcheck@10.2.252.181
Call-ID: 527910.2.252.181@10.2.1.13
CSeq: 2105 REGISTER
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Supported: replaces
Contact: sip:healthcheck@10.2.200.101
Content-Length: 0
<— Transmitting (no NAT) to 10.2.1.13:1046 —>
SIP/2.0 200 OK
Via: SIP/2.0/UDP 10.2.1.13:1046;branch=z9hG4bK16862;received=10.2.1.13
From: Server Iron sip:healthcheck@10.2.252.181;tag=14333
To: Server Iron sip:healthcheck@10.2.252.181;tag=as3cbb02e1
Call-ID: 527910.2.252.181@10.2.1.13
CSeq: 2105 REGISTER
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Supported: replaces
Expires: 0
Date: Fri, 30 May 2008 18:28:07 GMT
Content-Length: 0
Thanks,
G