Can a DS1 carried over SONET ever be used as a timing reference?
A. Yes. In many applications there is no other choice. Most switch remotes, for instance, obtain their timing from a specific DS1 signal generated by their host switch; so these remotes must line/loop time from the DS1 signal. In addition, DLC equipment, channel banks, and PBXs will not likely have external references and may be allowed to line/loop time from a DS1 carried over SONET. Five years ago all the literature however answered no to this question. See next question.
A. Yes. In many applications there is no other choice. Most switch remotes, for instance, obtain their timing from a specific DS1 signal generated by their host switch; so these remotes must line or loop time from the DS1 signal. In addition, digital loop carrier (DLC) equipment, channel banks, and PBXs are not likely to have external references and may be allowed to line or loop time from a DS1 carried over SONET. Five years ago all the literature however answered no to this question. See the next question for more information.
