The jitter specifications relate to hypothetical reference digital sections (HRDS) defined in Table 2/G.921. The limits given below have been derived on the basis that only a few digital sections will be connected in cascade and, moreover, no account has
ITU-T G.921-1988 history
1988ITU-T G.921-1988 DIGITAL SECTIONS BASED ON THE 2048 kbit/s HIERARCHY