S01. IF Payload == UDP/GTP-U THEN
S02.    Pop the outer IPv4 header and UDP/GTP-U headers
S03.    Copy IPv4 DA and TEID to form SID B
S04.    Copy IPv4 SA to form IPv6 SA B'
S05.    Encapsulate the packet into a new IPv6 header
S06.    Set the IPv6 DA = B
S07.    Forward along the shortest path to B
S08. ELSE
S09.    Drop the packet