I have an issue with Expressway C (8.9.2) and CUCM (11.5) with MRA and B2B configured.
When i try to call a MRA device, i see that the call arrived like a B2B call on the Expressway C and he don't find the destination because of the weird URI for the MRA device.
CUCM / 5560 ----- [TRUNK SIP B2B] ----- 5060 / Expressway C
I don't know why the expressway take this type of call like this
I agrea with you for the CMR, it is not my configuration... So i don't want to change all the configuration. But for the tests, i will delete the CMR Zone, restart the Exp_C and try again a call to a MRA device.
BTW, I don't see any search rule for your UC traversal zone, unless you didn't include it in your photo.
Look at my configurations for example (the relevant parts):
Maybe that's what's going on. You don't have a search rule for the MRA, so it find the next better match (somehow, not sure yet how) with the search rule that directs you to the B2B zone.
Please check this lead. I'm more optimistic about it.
I create your search rule as you can see,
But i have the same result,
And on the MRA deployment guide, it is not indicate to create this search rule as i have never created before