Page 533 - Handbook of Modern Telecommunications

4-64 CRC Handbook of Modern Telecommunications, Second Edition

expectations of performance. Extensions in writing are attached to valid SLAs; they are expected
to be signed by all participating parties.
13. Tracking changes: Changes in the client organization—for example, an increase in size or
acquisitions—can place unexpected traffic on the network, resulting in poorer response time.
Introduction of new applications can also change QoS and the cost of delivering it. Changes must
be documented, and parties must take into account the impact of these changes. If it is possible, a
test should be run with the changed traffic profiles. Test results must be attached to the contract.
14. Eligibility: SLAs are legal documents. The following three questions should be answered up
front:
• Authorization for signatures
• Representative persons
• Authorization of changes
15. Nonperformance: An SLA also defines nonperformance, or what is to be done when the indi-
cators do not meet the levels specified. However, some consideration has to be given to the
amount of deviation. For example, instead of requesting a 2-second response time, it is more
realistic to request a response time of 2 seconds for 90% of transactions, and 5 seconds for 99% of
transactions.
Actions against violating SLAs (IDG survey 2002):
• Impose the built-in SLA penalty (41%)
• Withheld payment for services (38%)
• Changed providers (31%)
• Renegotiated the SLA (26%)
• Gave poor recommendations to others (21%)
• Took no actions (12%)
• Took legal actions (7%)
16. Agreement on tools: Determining what measurement techniques and tools are going to be used
by contracting parties. Tools with standard interfaces for data collection, data processing, data
storage, and for reporting are preferred. A mutual access (read only) to data is recommended.
17. Help Desk services: SLAs represent partnerships between contracting parties. Usually, service
providers offer basic services, including:
• What services are supported
• Availability of the services
The basic service is actually a hotline; subject matter experts handle client notification and inqui-
ries. They are processed immediately or are referred to other experts. Availability is usually cor-
responds with contract item 6.
18. Escalation procedures: Contracting parties are expected to agree on the tasks, persons, priorities,
and timeframes of the escalation. Severity tiers may help to streamline the escalation processes.
Multiple tiers are recommended:
Tier 1: No dial tone in voice networks, and no packet transfer are service incidents that
require immediate attention.
Tier 2: Latency spikes, which can affect user response time. Sustained latency of, for exam-
ple, 250 ms or more for periods of longer than 1 minute may constitute another type
of escalation procedure.
Once tiers have been defined, customers should decide about the duration for which service pro-
viders are expected to trigger escalation steps and how quickly the customer may expect restored
services.
Names, job descriptions, and phone numbers for the individuals who will be directly respon-
sible for repairs must be identified. Reach numbers of individuals who must be notified must be
accurately identified.
Each tier will have a different escalation schedule, depending on the terms of the SLA.