[asterisk-users] Polycom SIP Phones On LAN can't register without WAN (Internet) Access

[Shawn Kelley]

We are having an issue that I have been unable to figure out how to resolve.
I think its related to the Polycom Phones and not the Asterisk
configuration, but I'm not positive.

We have several Polycom 500/501/601's on both a LAN and at employee homes.

The problem we are having is if our internet connection goes down the Local
LAN phones loose their connection to the Asterisk Server.
I've checked everything I can think of but can't figure out why its
happening.
I believe since the Asterisk Box is on the LAN and the phones are on the
same LAN then it shouldn't need internet to function.

The closest I have narrowed this down is to the DNS area. I found that if I
block access to our ISP's DNS that the phones aren't able to register with
asterisk.

This baffles me because the phone has the LAN address for the Asterisk
server so I don't know why it's doing DNS lookups.

Phone Example: (SIP 600)
        Phone's Config File:
        reg.1.address="254"
        reg.1.label="x204"
        reg.1.type="private"
        reg.1.thirdPartyName=""
        reg.1.auth.userId="254"
        reg.1.auth.password="mypass"
        reg.1.server.1.address="192.168.0.5"
        reg.1.server.1.port=""
        reg.1.server.1.transport="DNSnaptr"
        reg.1.server.2.transport="DNSnaptr"
        reg.1.server.1.expires=""
        reg.1.server.1.register="1"
        reg.1.server.1.retryTimeOut=""
        reg.1.server.1.retryMaxCount=""
        reg.1.server.1.expires.lineSeize=""

	Phone's IP Info:
        IP is 192.168.0.160
        IP Gateway: 192.168.0.1
        SNTP: 192.168.0.5
        DNS Server: 192.168.0.1
        DNS Alternate: 192.168.0.5

	Phone's Software:
		BootBlock: 2.4.0
		Bootrom: 3.2.1.0012
		SIP: 1.6.7.0098

The Asterisk Box has	2 Network Cards.
	1 on the LAN with IP of 192.168.0.5
	1 on the WAN with a public IP


Does anyone have any idea on what direction I need to go to resolve this?
Let me know if you need to know any further details about the configuration.
Also, FYI: when this occurs the logs show no activity on the Asterisk
server. No attempted subscribes/logins/registers.

Thanks in advance!!
--Shawn
shawn at sellersaide.com