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DID to FXO Back-to-Back setup

Hi everyone,

I’m new to voice and this is my first post. I’m planning to build a small lab in my home, I have 3 2811 router and I would like to use analog trunks between them..

I’m confused with the setup and configuration of the DID interfaces.

I’m planning to buy VIC-4FXS/DID and VIC2- 4FXO and connect them back-to-back my questions as below:

1) Can I connect three ports back to back as trunk and connect the remaining FXS port to an analog phone (can I mix the operation mode for each port)?

2) What type of cable I should use (rollover, crossed or straight) to connect the trunk and the analog phone?

3) Does misconfiguring the trunks can cause physical damage to the interfaces?

4) And if a customer has router with DID interface, what type of interface will be provide it from the Telco CO? (My understanding that CO only provide FXS interface)

thanks a lot.

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