I've searched around this board and other resources, but couldn't find an answer to my questions. What is required, besides having it enabled in a Voice Policy, for PSTN reroute to work? Do the users have to be at different sites? Do I have to setup and enable CAC for PSTN reroute to work?

Also, what triggers PSTN rerouting specifically? Is it when FE pools in different sites can't talk to each other?

PSTN Reroute takes effect when 2 Lync endpoints in different Network Sites are denied the ability to connect directly due to CAC Policy. This implies that setting up CAC is a requirement for implementing PSTN Reroute. The caller must have a voice policy that enables them to call the recipient's Tel URI via the PSTN.

• Marked as answer by Sharon.ShenMicrosoft contingent staff, Moderator Thursday, October 04, 2012 8:25 AM

PSTN Reroute takes effect when 2 Lync endpoints in different Network Sites are denied the ability to connect directly due to CAC Policy. This implies that setting up CAC is a requirement for implementing PSTN Reroute. The caller must have a voice policy that enables them to call the recipient's Tel URI via the PSTN.

• Marked as answer by Sharon.ShenMicrosoft contingent staff, Moderator Thursday, October 04, 2012 8:25 AM

PSTN Reroute takes effect when 2 Lync endpoints in different Network Sites are denied the ability to connect directly due to CAC Policy. This implies that setting up CAC is a requirement for implementing PSTN Reroute. The caller must have a voice policy that enables them to call the recipient's Tel URI via the PSTN.

• Marked as answer by Sharon.ShenMicrosoft contingent staff, Moderator Thursday, October 04, 2012 8:25 AM

PSTN Reroute takes effect when 2 Lync endpoints in different Network Sites are denied the ability to connect directly due to CAC Policy. This implies that setting up CAC is a requirement for implementing PSTN Reroute. The caller must have a voice policy that enables them to call the recipient's Tel URI via the PSTN.

• Marked as answer by Sharon.ShenMicrosoft contingent staff, Moderator Thursday, October 04, 2012 8:25 AM

PSTN Reroute takes effect when 2 Lync endpoints in different Network Sites are denied the ability to connect directly due to CAC Policy. This implies that setting up CAC is a requirement for implementing PSTN Reroute. The caller must have a voice policy that enables them to call the recipient's Tel URI via the PSTN.

• Marked as answer by Sharon.ShenMicrosoft contingent staff, Moderator Thursday, October 04, 2012 8:25 AM

OK, but what about when 2 endpoints can't connect because of a WAN failure? PSTN reroute will take effect then, won't it?

That is correct.

OK. I just completed a test using two Standard Ed. FE systems and placing a call between users assigned to the different pools. I put an ACL on a router between the two FEs to block them from talking to one another, and the call was re-routed over the PSTN. Works as advertised.

• Edited by LR Mark Williams Wednesday, October 03, 2012 8:32 PM grammar
• Marked as answer by Sharon.ShenMicrosoft contingent staff, Moderator Thursday, October 04, 2012 8:26 AM

OK. I just completed a test using two Standard Ed. FE systems and placing a call between users assigned to the different pools. I put an ACL on a router between the two FEs to block them from talking to one another, and the call was re-routed over the PSTN. Works as advertised.

• Edited by LR Mark Williams Wednesday, October 03, 2012 8:32 PM grammar
• Marked as answer by Sharon.ShenMicrosoft contingent staff, Moderator Thursday, October 04, 2012 8:26 AM

OK. I just completed a test using two Standard Ed. FE systems and placing a call between users assigned to the different pools. I put an ACL on a router between the two FEs to block them from talking to one another, and the call was re-routed over the PSTN. Works as advertised.

• Edited by LR Mark Williams Wednesday, October 03, 2012 8:32 PM grammar
• Marked as answer by Sharon.ShenMicrosoft contingent staff, Moderator Thursday, October 04, 2012 8:26 AM

OK. I just completed a test using two Standard Ed. FE systems and placing a call between users assigned to the different pools. I put an ACL on a router between the two FEs to block them from talking to one another, and the call was re-routed over the PSTN. Works as advertised.

• Edited by LR Mark Williams Wednesday, October 03, 2012 8:32 PM grammar
• Marked as answer by Sharon.ShenMicrosoft contingent staff, Moderator Thursday, October 04, 2012 8:26 AM

OK. I just completed a test using two Standard Ed. FE systems and placing a call between users assigned to the different pools. I put an ACL on a router between the two FEs to block them from talking to one another, and the call was re-routed over the PSTN. Works as advertised.

• Edited by LR Mark Williams Wednesday, October 03, 2012 8:32 PM grammar
• Marked as answer by Sharon.ShenMicrosoft contingent staff, Moderator Thursday, October 04, 2012 8:26 AM

This was a very interesting explanation about "PSTN rerouting"

Intercluster Routing Component

The Intercluster routing component is responsible for routing calls to the callees primary Registrar pool. If that is unavailable, the component routes the call to the callees backup Registrar pool. If the callees primary and backup Registrar pools are unreachable over the IP network, the Intercluster routing component reroutes the call over the PSTN to the users telephone number.

https://technet.microsoft.com/en-us/library/gg425812.aspx

Hello,

PSTN reroute is triggered in case of call forwarding as well as simultaneous ringing as well.

Regards

Sushant