Anyone out there might help me to point on the right direction about why the top down did not work automatically when I shutdown a voice-port E1 in the first gateway listed on route group? However, it worked when I manually changed the priority from below to top.

For instance: site A - RG_A (top down): on the top 10.x.x.1 (site A), below 10.x.x.2 (site B)

I shutdown the voice-port and/or dial-peer pots to the PSTN on site A, but the call did not get redirected to the Site B. However, when I manually moved site B to the top, then the call worked through site B.

The call flow is the same for Site A and B: PSTN - E1 - H.323 - CM 8.6

It looks like either I missed something very basic or the call manager did not receive the link to the PSTN was down, therefore, did not even try to the next gateway available.

Thoughts? Thanks in advance for any help.