Telephone User Part (TUP)
Encyclopedia
Telephone User Part provides conventional PSTN telephony services across the SS7
network. TUP was the first layer 4 protocol defined by the standards bodies and as such did not
provision for ISDN services. It has now largely been replaced by ISUP. However, it can still be found in operational use in some parts of the world (eg China).
TUP is defined in ITU-T
Recommendations Q.721-725. These define the international telephone call control signalling functions for use over SS7
.
Various national variants of TUP have evolved, some of which provide varying degrees of support for ISDN. E.g. French SSUTR2
and Chinese TUP (Specification GF001-9001).
SS7
SS-7 can stand for:* Signaling System #7, a set of telephone signaling protocols.* The R-16 missile, with NATO reporting name SS-7 Saddler.* China Railways SS7, an electric locomotive model in China.* Super Socket 7, a chip socket introduced by AMD...
network. TUP was the first layer 4 protocol defined by the standards bodies and as such did not
provision for ISDN services. It has now largely been replaced by ISUP. However, it can still be found in operational use in some parts of the world (eg China).
TUP is defined in ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
Recommendations Q.721-725. These define the international telephone call control signalling functions for use over SS7
SS7
SS-7 can stand for:* Signaling System #7, a set of telephone signaling protocols.* The R-16 missile, with NATO reporting name SS-7 Saddler.* China Railways SS7, an electric locomotive model in China.* Super Socket 7, a chip socket introduced by AMD...
.
Various national variants of TUP have evolved, some of which provide varying degrees of support for ISDN. E.g. French SSUTR2
SSUTR2
French SSUTR2 is the French national variant of the Telephone User Part ....
and Chinese TUP (Specification GF001-9001).