Interconnection of DWDM Rings

Hello, antonioli.
It's nice to meet you in the community.
We're working on your problem. Please be patient.

Dear antonioli!
For your first question, the second solution is better.
The first topology belongs to the ring tangent scenario. The second topology belongs to the ring intersecting scenario, the network survivability of this topology is better.

Thanks. And about the devices interconnection?

Dear
1,because of it's  backhaul network so do not mix two different vendor's equipment in same ring.suggestion make two 5 sites ring by different vendor.
2, make dual interconnection is better and different ring connection each other by T (service) board as service requested, the equipment of one vendor is used as the client equipment of another vendor.Facilitates service provisioning and fault locating. Also there will have ring protection and site protection .
3,some vendor's equipment with different ODUx sequence,but If the port protocol, rate, and encapsulation mode,etc are the same, they can be interconnected.

4,because of the question was on huawei web site so i have to say please replace the X vendor's equipment by huawei's and on the connection site we can set as ROADM site.Use X vendor devices to construct the second plane

dear
for interconection it's depond on you service,you can visit the following links to check the hardware description
https://support.huawei.com/hedex/hdx.do?docid=DOC1000450805&lang=en

Sorry for the spam - and physically connected via cable in which cards?

Dear friend！
You can directly use optical fiber to transfer on the tributary board. The tributary board supports the access to many kinds of client-side services. such as:

or：

Thank you！

Something like that?

Yes, you are right!
Please note that when you do service transfer, the speed class and service type on both sides must be set the same.