Emergency Login Service
Provides ssh access to admins in the event of a routing failure. (ie, it has an externally facing independent ssh service)
This runs on port 2222 on (router|ace).tardis.ed.ac.uk to avoid filling the logs due to probes from alarmingly prevalent ssh worms.
Note that some environments will firewall outgoing connections on this port, but we assume most admins have a suitable platform from which to connect.
Also, there is a monitor and keyboard in the Tardis room connected to leela, which can be used in emergencies.