Asterisk as a recording server

Dear all, I’m analyzing a project to add on-demand recording (using DTMF) to a legacy PBX with 4 PRI.
I’m thinking about intercept with two mediagateway (or PRI card) the PSTN line and add an Asterisk box in the middle.
Something like that:

Legacy PBX => (PRI) => MEDIA GATEWAY => SIP => ** Asterisk ** => SIP => MEDIA GATEWAY => PRI => TELCO

This is a working solution (I think) but the Asterisk box is a single point of failure, is there any way to record on demand using Asterisk by “monitoring” / SPAN the 4 PRI or the SIP trunk without an inline setup?

P.S. directmedia (between media gateway) isn’t working with DYNAMIC FEATURES right?

Anyone have better ideas?


Why are you doing a SIP leg between the PBX and your Telco?

You could get a two-port PRI card and keep everything TDM.

Legacy PBX <PRI> Asterisk Box <PRI> TELCO

You wouldn’t need to use any media gateways in that case.

It can be another way but I’m looking for a solution where Asterisk isn’t (if possibile) inline during calls.
It there some HW to split/clone the PRI between PBX and TELCO to an Asterisk PRI card?
My goal is to not block calls if the Asterisk server have some issues.

Is this associated channel signalling or common channel signalling. WIth the latter, Asterisk would have to react to the protocol exactly the same as the real destination for a passive tap to be reliable.

It’s E1 PRI so I think CAS.