Service Levels

Establishing Appropriate Service Levels for a Network

Brian Kozma

Network and Telecommunications II NTC/410

Facilitator: J. Edwards

University of Phoenix

November 04, 2006

Service Levels Memorandum

________________________________________

DATE: 04/11/2006

TO: J. Edwards

FROM: Brian Kozma

SUBJECT: How appropriate service levels can be established for a network

Introduction

Before analyzing the performance of any network, a set of measurable criteria for performance must be established. The purpose of the measurable criteria should state what is expected of the system in specific terms such as, Availability, Reliability, Response times, and Throughput.

Availability

Availability means the system is ready for immediate use. For example, an airplane must be very reliable, while in the air, but aren't expected to fly 24 hours a day. Reliable components certainly contribute to having a reliable network, but network availability is also controlled by other factors, including how rapidly a network can recover from a failure.

The System

As stated above, each phone has certain basic information about the network pre-programmed within the phone. As soon as the phone is connected to the network, it will begin a preprogrammed effort to contact the Call Manager, and register itself with the unit. This accomplishes two major things: first, it identifies to the Call Manager the return path to this specific phone, and secondly it identifies that phone as an available resource.

Once the registration process is complete, the phone is ready to use. The user can then pick up the phone, and dial another phone on the system. The far end phone will ring, and the callers are connected. At the conclusion of the call, the users hang up and the call is disconnected. What happens behind the scenes is as follows: Phone A (the initiator) goes off hook, and signals the call manager that a call is in process. The digits dialed on Phone A are transmitted to the Call Manager, who compares this number to a preprogrammed database. Assuming the Call Manager knows about Phone B, Phone B is signaled and is supplied ring tone. Once Phone