Yes, attaching C3Ts to an internal LAN which has connection with the CCASS/3 network is one way to access CCASS/3. However, Participants electing this access method should be aware of the need to implement Network Address Translation (NAT) when setting up their internal LAN. Each CCASS Participant is pre-assigned a range of IP addresses for defining his own C3Ts. CCASS/3 will validate the IP address when Participants attempt to logon CCASS/3 via C3T. When a Participant set up internal LAN in his office, the internal LAN may carry IP addresses different from the ones pre-assigned by HKSCC. Under such situation, Participant should implement NAT so that CCASS/3 is able to recognise the IP address assigned to the C3T. In addition, the NAT should be a one-to-one mapping of the C3T. That is, IP address of each C3T should be translated to a unique value within the original IP address range. Similarly for Clearing Participants to access RAP, a set of IP addresses should be pre-registered with HKSCC, where RAP will validate the IP addresses when Clearing Participants attempt to logon to RAP.