You are not precise on your requirements, but I will try to explain the options. You said you will have 2 lines. I assume you mean 2 phone numbers. You will define 2 trunks, 1 for each phone number.
Here are your routing options:
1. Trunk#1 routed to phone port 1, trunk#2 routed to phone port 2
2. Either trunk can be routed to both phone ports
3. Either trunk can be routed to the other phone port or another OBi202 when the phone is busy or unanswered
4. If both OBi202s have the same trunks defined then a call to trunk#1 will ring both OBi202s, so there is no need to forward the call to the other OBi202 when the phone is busy.
The phone ports are separate and each has its own dial tone. There is an option for Barge-In. When a phone is on an active call, the other phone can join by calling the 1st phone. I don't have an OBi202, so I don't know if there is a tone when barged in. I suspect there is. I don't think the 2nd phone can pick up an un-answered call on the 1st. It would have to be forwarded.
Some providers allow dual registration and others don't. GV allows dual registration, so a call to your GV number will ring both OBi202s. Some providers don't allow dual registration, so you will have to setup a sub-account for the 2nd OBi202 plus some routing rules at the provider. If you have to setup sub-accounts then the OBi202 configurations will be different. If you need call forwarding to the other OBi202, the configurations will be different.
