eCAL 6.0.1 ↔ eCAL 5.11.8 compatibility (TCP pub/sub, multicast v1 vs v2)

[edwardstevenw]

I’m transitioning a system from eCAL 5.11.8 to eCAL 6.0.1 and wanted to confirm whether there are any compatibility issues between these versions for:

• TCP pub/sub
• UDP, especially multicast

In the eCAL 6 ecal.yaml I see the UDP config version setting:

# Transport layer configuration
transport_layer:
  udp:
    # UDP configuration version (Since eCAL 5.12.)
    # v1: default behavior
    # v2: new behavior, comes with a bit more intuitive handling regarding masking of the groups
    config_version: "v2"

My questions:

1. Does transport_layer.udp.config_version only affect UDP (multicast) transport (e.g., multicast group calculation / masking), or can it also affect TCP pub/sub in any way?
2. With a mixed setup (publisher on eCAL 6.0.1, subscriber on eCAL 5.11.8), is TCP pub/sub expected to be compatible and stable?

Context: In my application I primarily use TCP pub/sub, but I still want to understand the expected behavior when running mixed versions during the migration.

[KerstinKeller]

Hi @edwardstevenw,

eCAL needs UDP for a) registration traffic and b) user traffic. The configuration however only affects user traffic, so I would say that you can safely update.
The tcp_pubsub protocol / transport has not changed at all, so I expect the transport to be completely compatible and stable.

What might be a bit tricky is to configure both systems (via old ecal.ini and new ecal.yaml) in such a way that they are compatible.
E.g. both configurations need to have network enabled...
It might be a bit safer, if you took an intermediate step to migrate first to 5.13 and then to 6.0, if you do run into issues with a direct migration.

However, if you run into issues, we're happy to help.

[edwardstevenw]

Thank you, that clears it up and answers my question. I’ll proceed with the update.