We will be rebuilding our container hosts in Manchester to reflect a decision to change host operating system.
Manchester is technically deprecated and we advised changes running up to scaling it back in February, last August - http://blog.simwood.com/2018/08/network-changes/
. Therefore, Manchester specific SIP host names already point to other sites and whilst direct IP addresses still work, our interop specifies that customers should not send directly to an IP address and, if doing so is unavoidable, customers should configure their own fail-over to other sites. Therefore, whilst these addresses will go offline during this maintenance but it should not be service affecting for anyone configured properly.