Actually, only three GV accounts — to do what you want you must have at least one SP configured for SIP (even if it's not an actual working SIP account) as explained below.
If you have the linksys phones at fixed IP addresses then you may be able to send calls to them by following the instructions in
this article (consider the Linksys phone as a substitute for the Asterisk server - the main thing to pay attention to is the use of the Voice Gateways). HOWEVER, note a couple of things:
The example shows an Access Number setting of
SP2(192.168.0.100) where 192.168.0.100 is the IP address of the Asterisk server. You can use any of the SP's (doesn't necessarily have to be 2) but it must be one associated with a SIP account, so at most you can only have three Google Voice accounts on your OBi202, because one SP slot must be configured for SIP. If you're not using any real SIP providers then see
this message for how to set up a "dummy" SIP account that will work for this purpose. You CAN use multiple Voice Gateways (all referencing the same SP) and set a different ip addresses (and, optionally, port designations) on each, so that might allow you to direct calls to a specific phone, or a specific line on a multi-line phone. For example, if you had a four line SIP-based phone at 192.168.0.50 and it was configured to use port 5063 for calls to line 4, then you should be able to send a call to Line 4 by using
SP2(192.168.0.50:5063) as the Access Number in the Voice Gateway, assuming SP2 is configured to use a SIP account.
These other threads MIGHT also help you:
http://www.obitalk.com/forum/index.php?topic=1875.0http://www.obitalk.com/forum/index.php?topic=2454.0http://www.obitalk.com/forum/index.php?topic=113.0http://www.obitalk.com/forum/index.php?topic=205.0