IP Telephony Interconnection Reference

interConneCtion PrACtiCes in Pstn 73

5.9 Technical Characteristics

5.9.1 Interconnection Circuits Transmission Characteristics

Interconnection circuits should be supported in PDH (Plesiochronous

Digital Hierarchy) or SDH (Synchronous Digital Hierarchy) tech-

niques. PSTN interconnections are usually done considering 2 Mb/s or

multiple rates interfaces according to G.703 ITU-T recommendation.

Presently, temporized interconnection between Operators is struc-

tured around a basic transmission network unit, the 2 Mb/s circuit. If

the basic interconnection capacity unit were a 2 Mb/s circuit, the capac-

ity to be purchased by an Operator would then be a multiple of 2 Mb/s.

e frame structure at the 2048 Kb/s is according to the European

Commission ...