Dual RAP Mesh Network vs PTP Wireless Ethernet Bridging to provide link redundancy

Question

Currently looking at a few options to optimize a current point-to-point wireless LAN-to-LAN connectivity shot for a wired customer site for better redundancy (hardware diversity and/or logical path diversity). Currently the customer is fed via an older solution, using two Cisco 1522 APs with Cisco Aironet 14-dBi Path Antennas (AIR-ANT5114P-N) for a 5-GHz PTP wireless ethernet bridge (under 3km), in which one 1552AP hangs off a L3/L2 Distro switch and the customer's 1522AP hangs off a 3750X switch, which has another access switch hanging off it via a fiber run of about 2km, which is exposed in parts and can't be re-run again due some limitations.The customer doesn't utilize any wireless services. Due to their location, we can't connect them to our wired distro infrastructure directly via fiber.
Looking at setting up two wireless shots (instead of just one currently used); 5-GHz point-to-point bridges using upgraded gear: Cisco 1552EU APs with Cisco Aironet 14-dBi Path Antennas (AIR-ANT5114P2M-N) or straight Exalt r5005 solution. The PTP shot will hang off two seperate distro switches for redundancy purposes, pointing toward the customer site at two seperate locations, spaced apart by approximately 1 to 1.5 km, so that they aren't at the mercy of being isolated on one side if they have another fiber cut which connects their two main access switches together. If need be, we can hang two main APs on one distro facing two APs at the customer site, since this would create some redundancy, just not the same level as above.
The below is what I'm really unsure on.
Possibly looking at setting up a mesh network using Cisco 1552E APs with 2.4 GHz Omni-directional antennas (either a 2.4/5GHz Terrawave MIMO Omnidirectional antenna or Cisco AIR-ANT2547V-N antennas, which ever is best) with two RAPs, one RAP hanging off one distro and the other RAP hanging off another distro for hardware diversity, both under the same bridge group name and both RAPs hanging off the same WLAN management SVI subnet on the distros. The customer site will have two 1552E MAPs located at two seperate sites, as pointed out above. I don't think a third AP would be needed, since they don't use wireless services. Since there would be only two RAPs, not three, would it be best two set-up this with both RAPs on the same channel to minimize convergence time should the mesh transfer from one RAP to the other RAP, as long as both RAPs are spaced apart under ???? distance to avoid interference/other issues? Looking at some documenation, it appears you can have a MESH network, as long as your MAPs and RAPs fall within a 2 mile range area, preferably closer to a 1 mile range area (for better bandwidth & reliability). This solution has been brought up as possible dual-homed solution in theory, by virtue of having two more more MESH APs fall within the range listed above, to the RAPs. From a layer 3 perspective, I'm not sure what the most optimal idea to run with in this scenario set-up would be. Possibly set-up two seperate user SVI VLANs (for their data services), one placed on each access switches these MAPs will hang off at the customer site, & using the same management SVI subnets as the RAPs for the wireless managment side (for accessing the APs). From my understanding, the user data SVI doesn't matter from the perspective of when the mesh transfers from one RAP to another, it should be transparent to them. The distro switches will just have the management SVIs placed on them for the RAPs, the user SVIs will be placed local on the access switches only. And all APs will hang off access ports set to the management VLAN ID.
In my opinion, the PTP 5-GHz, dual distro homed solution makes the most since for wired client access, but since the latter option was brought up, it has to be weighed - plus I'm curious if it can work.

Answer 1

The Exalt r5005 works great for redundancy PTP links. You have to use the sync cable between the two co-located bridges and also set the polarization on the bridges.  You can then use routing or spanning tree to decide traffic path.  With mesh, you will have to make sure you set the parent or else the maps will keep switching perhaps.