As you know, MSS can use Gtalk as external line to bridge Gtalk and SIP networks. It is a good idea and we are happy to provide this feature for our customers.
But since Google gives up Gtalk, it seems we have no choice to discard it. We update MSS V18 today to cut Gtalk out.
Gtalk is good, but time to say good bye now. If you are still using this feature, you can keep your MSS at V16 which is LTS version and we will maintain it for at least one year.