Core design difference.

In monolithic networks, the MSC will perform both analysis and routing. It means both analysis and switching are performed by the same node. This will have some increased load in the MSC performance and greater hardware.

In layered architecture, there are two nodes with MSC server for analysis and Media Gateway for switching of the calls.

Why the maximum number of links per link set in SS7 is limited to 16

The SLS field or Signaling Link Selection field is 4 bit length. Thus the range of the field is from 0 to 15 or 16. This imposes a restriction that at a maximum 16 links can be defined in a link set. If additional links are needed, then a new point code has to he created to support the additional links.

thanks,
ram