MSC/VLR functionalities are similar witha.GGSNb.SGSNc.HSSd.HLR

The functionalities of MSC/VLR (Mobile Switching Center/Visitor Location Register) are more similar to HLR (Home Location Register).

Here's why:

a. GGSN (Gateway GPRS Support Node) - This is not similar to MSC/VLR as it is part of the GPRS (General Packet Radio Service) core network that sends and receives data packets over the internet.

b. SGSN (Serving GPRS Support Node) - This is also not similar to MSC/VLR as it is responsible for the delivery of data packets from and to the mobile stations within its geographical service area.

c. HSS (Home Subscriber Server) - This is a central database that contains user-related and subscription-related information. While it does have some similarities with MSC/VLR, it is not the most similar.

d. HLR (Home Location Register) - This is the most similar to MSC/VLR. Like MSC/VLR, HLR is a database used for storage and management of subscriptions. The main difference is that while HLR is responsible for permanent data storage, VLR is responsible for temporary data storage.