How Many IP Addresses at Serving Gateway for GTP Protocol

Hello, I am Deni Yulianti. I have a doubt. How many IP addresses that are located at Serving Gateway?
Because in GTP version 2 protocol for a message “create session request” from MME to SGW, on pcap, I have seen it will be established 3 tunnels namely, S11 (MME-SGW) for control plane and S5 (SGW-PGW) for user plane and control plane. However, the IP address of SGW is totally different with original SGW. It happens also for a message “create session response”, it will be established 3 tunnels as well. Nevertheless, S5 (SGW-PGW) for both user plane and control plane use different IP address with original IP at SGW. Next, S1-U (SGW-eNodeB) for user plane, basically the IP address is belong to which node SGW or eNodeB?

Please help me out. My email address is deniyulianti@gmail.com. Thanks in advance.