In the router access list, you will need to add the following entry:
 

! PCAnywhere entry!
access-list 151 permit udp host 155.245.163.7 eq 22 host 193.62.83.170 gt
1023 log
access-list 151 permit udp host 155.245.163.7 eq 5632 host 193.62.83.170 gt
1023 log

!End entry!

This translates to allow UDP access from host 155.245.163.7 (the machine brims7.essex.ac.uk) port 22 to host 193.62.83.170 (the local machine grape.ukerna.ac.uk on which the client is running) on ports above 1023 and log traffic. Similarly access needs to be opened from port 5632 on the remote machine to a port above 1023 on the local machine.
The IP address 193.62.83.170 will need to be changed to the address of the machine which is to be used for the session.