ABSTRACT
Customer has no control and little interest. e technical aspects, called Service Level Specifications, are based on the analysis and
conjugation of several elements into technical clauses and actions, dependent on, for example:
• If the Client CPE (Customer Premise Equipment) is up and running
• If backup links or connections became active (e.g., leased line, ADSL, ISDN, mobile)
• MTTR (Mean Time To Repair) • If a backup facility was activated • RTD (Round Trip Delay): Of voice payload, of mission criti-
cal data payload, etc. • One-way delay variation (a.k.a., Jitter): Of voice payload, of
mission critical data payload, etc. • Packet loss: Of voice payload, of mission critical data pay-
load, etc. e last three parameters are very important to VoIP (Voice over IP)
service offerings. It is noted2 that if end-to-end one-way delays are kept below 150 ms, most applications will not be significantly affected.
