Standards
R2 signalling refers to a vast number of variants of R2 that resemble each other to varying degrees. For most R2 variants, each such variant of R2 is promulgated by the PTT of each nation and/or by a telecommunications equipment manufacturer who addressed that national market with a nation-specific adaptation of one of their products.
The international version of R2 is an inter-nation protocol for R2 signalling that crosses national boundaries, and is neither a superset nor a subset of any national variant of R2. Conversely, each national variant of R2 is intra-nation. The international standard R2 was first promulgated by CEPT in the 1970s and then later by ITU-T with only modest evolution.
Read more about this topic: R2 Signalling
Famous quotes containing the word standards:
“As long as our people quote English standards they dwarf their own proportions.”
—Ralph Waldo Emerson (1803–1882)
“A generation which has passed through the shop has absorbed standards and ambitions which are not of those of spaciousness, and cannot get away from them. Everything with them is done as though for sale, and they naturally have in view the greatest possible benefit, profit and that end of the stuff that will make the best show.”
—Alexander Herzen (1812–1870)
“The things a man has to have are hope and confidence in himself against odds, and sometimes he needs somebody, his pal or his mother or his wife or God, to give him that confidence. He’s got to have some inner standards worth fighting for or there won’t be any way to bring him into conflict. And he must be ready to choose death before dishonor without making too much song and dance about it. That’s all there is to it.”
—Clark Gable (1901–1960)