SCTP Protocol (Networking)

Question

I have been reading about the SCTP, SS7 and SIGTRAN protocol. But I have a few doubts, I would like to know if someone who specializes more in networks can answer it. (I am a security auditor)

1. Can the SCTP protocol be used in other fields than just telephone communication (landline and mobile)?

2. Could it be said that the SS7 protocol is similar to the Internet Protocol (IP) but in telephony?

3. What is the most significant difference between SS7 and SIGTRAN?

4. Finally, is a PSTN (Public Switched Telephone Network) only for fixed telephony (homes) or also for mobile telephony (Cellular)?

Thank you for your answer,

Answer 1

1. Can the SCTP protocol be used in other fields than just telephone communication (landline and mobile)?

Yes, it can be used in other fields. SCTP is a protocol in the Transport Layer of the Internet Protocol Suite, that has its own advantages and disadvantages. For example it is used in WebRTC for the Data Channel.

2. Could it be said that the SS7 protocol is similar to the Internet Protocol (IP) but in telephony?

SS7 is not a single protocol but a set of telephony signalling protocols that includes protocols from all OSI layers so the comparison to a single (IP) protocol is not correct.

3. What is the most significant difference between SS7 and SIGTRAN?

SIGTRAN is SS7 over IP. The application layer protocols are the same (MAP, ISUP, CAMEL, ...) while the physical to transport layer (1 to 4) protocols are different. In SS7 you have MTP 1, 2 and 3 while in SIGTRAN you have IP, SCTP, M2PA, M2UA, M3UA, SUA protocols.

4. Finally, is a PSTN (Public Switched Telephone Network) only for fixed telephony (homes) or also for mobile telephony (Cellular)?

According to Wikipedia the PSTN includes the mobile networks.

Originally a network of fixed-line analog telephone systems, 
the PSTN is now almost entirely digital in its core network
and includes mobile[1] and other networks, as well as fixed telephones.[1]