Hi
There are limitations exists for the GW Nodes you associate and SS7 links on PGW, but there is no limitation for creating the Session set in PGW.
Under the session set in PGW, there is a limitation defined for no. of links / ss7 session set in the XECfgParm.dat file. You can verify the component related limitation on the same file.
*.maxLinksPerSessionSet = 4 # max links per SS7 sessionSet
Thanks.