Diameter vs SS7
Diameter and SS7 are signalling protocols generally used in telecommunication systems. syst ems. Dia Diamete meterr is hig highly hly used in 3GP 3GPP P late latest st rele releases ases for AA AAA A services services (Authentication, (Authent ication, Authorizatio Authorization n and Accounting, Accounting, !hile SS7 !as initially used !ith PS"# and GS$ net!or%s for digital signalling &et!een different nodes for call management and other services management. Diameter protocol run over the 'P net!or%, !hile SS7 can &e used in digital channels such as on ) &ased "D$ ("ime Division $ultiple*ing net!or%s directly. Diameter
Diameterr prot Diamete protoco ocoll !as der derived ived fro from m +AD +AD'S 'S (+e (+emote mote Authent Authenticat ication ion Dia Diall 'n ser Service protocol !ith a num&er of improvements. "his protocol is used !idely in 3GPP +elease - on!ards, !here there is a need for AAA services. merging ne! technologies in communication that have &een &uilt on total 'P net!or%s have sho!n an increased reuirement for access control mechanisms more than ever due to sec security urity concerns. concerns. "he "herefo refore, re, Diam Diameter eter pro protoco tocoll !as developed as a frame!or% for future AAA services !ith enhancements to e*isting +AD'S protocol. Diameter protocol !as designed as peer to peer architecture even though, it loo%s li%e a server client protocol in the implementation. As per the Diameter protocol there is a node called diameter agent, !hich does either message relay, pro*y, redirecting or translate function. Since Diameter protocol uses synchronous message e*change format, there are specific responses for each reuest message. 't uses Attri&ute /alue0Pairs (A/Ps to transfer these messages &et!een nodes. Diameter uses 'P net!or%s as its medium, and runs on top of "1P ("ransport 1ontrol Protocol or S1"P (Signalling 1ontrol "ransport Protocol, !here it can have more relia&le communication. SS7
SS7 (Signalling System #o. 7 !as developed to call management and service signalling reuirements reuirements of the digital net!or%s &ased on the full duple* channels. channels. 'n general, different variants are developed all over the !orld for SS7 !here, #orth American version is called 11'S7, !hile uropean version is called 11'"" SS7, even though there is one version defined &y '"0" in its 27 series. 'n SS7 SS 7 ne net! t!or or% % st stru ruct ctur ure, e, th the e no node des s ar are e ca call lled ed si sign gnal alli ling ng po poin ints ts,, !h !hil ile e th the e connecti conn ection on &et! &et!een een thos those e nod nodes es is cal called led sign signalli alling ng lin% lin%s. s. 'n SS7 net!or%s net!or%s Signalling "ransfer Points (S"Ps are introduced to relay and route the messages &et!een signalling points. SS7 has point to point architecture !ith one to one physical correspondence &et!een t!o signalling points. SS7 structure initially developed to have compati&ility !ith 4S' (4pen Systems 'nterconnection model as !ell. $essage "ransfer Part ($"P ) to 3 used in SS7 are similar to 4S' first 3 layers, laye rs, !hi !hile le S11 S11P P (Sig (Signal nalling ling 1on 1onnect nection ion 1on 1ontrol trol Prot Protoco ocol l in SS7 prot protoco ocoll
provides the connectionless or connection oriented communication &et!een signalling points. What is the difference between Diameter and SS7?
5 6oth SS7 and Diameter are signalling protocols that are used in different eras of telecommunication. 5 Diameter protocol provides communication &et!een net!or% nodes !ith enhanced access control on top of 'P net!or%, !hile SS7 protocol defines all layers of 4S' !ith support for legacy "D$ ("ime Division $ultiple*ing net!or%s. 5 As per the diameter, the net!or% node can act as either a client or a server for t!o different connections, !hile in SS7 each node is given a separate signalling point code to identify them !ithin a net!or%. 5 As per the '$S ('P $ultimedia Su&system architecture and latest 3GPP releases, most of the interfaces use Diameter protocol, !hile GS$ architecture (G net!or%s uses SS7 protocol. SS7 signalling can &e implemented on top of 'P net!or% in order to support the nodes that do not have diameter functionality using a signalling gate!ay !hich function the inter!or%ing &et!een different layers of SS7 and 4S'. 5 6oth protocols are used for communication &et!een net!or% nodes, !here SS7 protocol mostly focuses on all call management and other service level communications, !hile Diameter protocol mostly gives the access control and accounting &ased services on top of 'P net!or%.
