ssnid - external loadbalancing

Hello

We have 2 business connectors installed. Each of it responds with a different part in the session cookie “118” and “120” see below.
Are these parts identifiers for the servers?
Where can I config this value?

xxxxxxxxxxx=5555-118
xxxxxxxxxxx=5555-120

We want to use an external loadbalancing mechanism and use this part of ssnid to hold the session on bc server.

  • Is this a solid architecture?

Regards
Ulrich Scherb