ITM 301 Lecture Notes - Lecture 7: X.25, Fault Tolerance, Symmetric Digital Subscriber Line

• School: Ryerson University
• Department: Information Technology Management
• Course: ITM 301
• Professor: Farid Shirazi

Document Summary

These two topics will be on the final exam from the first half of the course. Remote access technology: pstn (public switch telephone net, telephone (modem) based communication system. Provides 2 comm channels 64 kps each (can be combined to provide 128 kps) Provides 1 d-channel (control and management) 16kps. Note: you can not use d-channel for sending/receiving data. It provides 23 communication channels 64 kps each = combined 1. 544 m/s. 1800 numbers are never busy because there are 23 channels waiting for someone to call. It provides 1 d-channel 64 kps: t-series (dedicated comm lines) Digital lines, using tdm (time division management) Relia(cid:271)le a(cid:374)d (cid:862)se(cid:272)ure(cid:863: x. 25/ frame relay. X. 25 is the oldest packet switched communication network. It is the first technology that integrated telecom into an ip based packet exchange. It offers a maximum speed of 2 m/s. A faster packet switch network is called frame-relay.