Subject: Comments on Policy Terminology

From: "Jonatan, T.H." <[email-masked]>
Date: Fri, 11 May 2001 17:57:51 +0100

Hi,

I find the definition about SLA, SLS and SLO are somewhat confusing.

$ Service Level Agreement (SLA) (P) The documented result of a negotiation
between a customer/consumer and a provider of a service, that specifies the
levels of availability, serviceability, performance, operation or other
attributes of the service. (See also "Service Level Objective.") [R2475]

$ Service Level Objective (SLO) (P) Partitions an SLA into individual
metrics and operational information to enforce and/or monitor the SLA.
"Service Level Objectives" may be defined as part of an SLA, or in a
separate document. It is a set of parameters and their values. The actions
of enforcing and reporting monitored compliance can be implemented as one or
more policies. (See also "Service Level Agreement.")

IMHO SLO can both exist in SLA and SLS but the way it is presented in SLA
and SLS is different (i.e. business-oriented way as oppose to technical
oriented way).

$ Service Level Specification (SLS) (P) Specifies handling of a customer's
traffic by a network provider. It is negotiated between a customer and the
provider, and defines DiffServ parameters (such as specific Code Points and
Per-Hop-Behaviors, profile characteristics and treatment of the traffic for
those Code Points). An SLS is a combination of an SLA (a negotiated
agreement) and its SLOs (the individual metrics and operational data to
enforce). (See also "Service Level Agreement" and "Service Level
Objective.")

This definition is confusing because:
SLA defitinion gives an impression that SLA is the whole thing about the
service written in business oriented perspective while SLS definition gives
an impression as if it is a technical interpretation of SLA (as operational
guideline for traffic handling). But then it mentions that SLS is "a
combination between" SLA and SLO which suggest that SLS is the whole thing.
So is SLS bigger than SLA or the other way around or they both at the same
level but address different perspective?

Regards,
Tjaja

---

From: "Andrea Westerinen" <[email-masked]>
Date: Fri, 11 May 2001 15:08:28 -0700

Perhaps we could modify the problematic sentence slightly as follows ...

An SLS is a specific SLA (a negotiated agreement) and its SLOs
(the individual metrics and operational data to enforce) to guarantee
quality of service for network traffic.

Andrea

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]]On Behalf Of Jonatan, T.H.
Sent: Friday, May 11, 2001 9:58 AM
To: [email-masked]'
Subject: Comments on Policy Terminology

Hi,

Regards,
Tjaja