Side_1_360

7.3 All-in-one Relationship between

SLA and SLS

In this case, the SLA includes all IP-based ser-

vices provided using the same IP service. A full

description of the QoS parameters that are neces-

sary on the application/service level for all the

IP-based services is given. Bearing in mind their

QoS parameters and traffic profile, the QoS

parameters and values of the IP basic service

may be described as one QoS description or

several (depending on the way the basic service

is used).

As illustrated in Figure 14 a single SLA

envelops the service descriptions for all services

(A, B, C), as well as one SLS which includes

QoS descriptions for each of the services (i.e.

QoSa, QoSb and QoSc), as well as a QoS

description of the common IP service QoSIPtot.

Note that QoSIPtot includes the requirements

and parameters from all QoS descriptions and

demands given in QoSa, QoSb and QoSc.

In the case of a provider offering bundled ser-

vices, i.e. usually combining several services

into one common (bundled) service delivery,

this type of SLA is very important. All-in-one

relationships are traditionally present in the case

of monopolistic operators that are responsible

for the full service package, i.e. all services

delivered to the users. The user would then have

an agreement with a single (so-called primary)

provider that will be responsible for the delivery

of other services offered by other providers (e.g.

service provider, content provider, etc.) that are

using the connectivity service offered by the pri-

mary provider.

Figure 15 illustrates the case where an NO is

the primary provider for the user and he needs

to take care and agree the SLAs with all the pro-

viders (e.g. SP A, SP B) that are contributing to

the service(s) delivered to their users. In such a

case the “all-in-one” relationship is usually pre-

sent.

8 Concluding Remarks

While numerous research projects are trying to

solve the support of the future QoS-aware IP ser-

vices by introducing the concept of SLAs, the

practice is rather unclear.

Existing SLAs involve no ‘hard’ QoS guarantees

for IP-based services, where the parameters are

strictly defined, objectively measurable with the

desired granularity and where the values are set

to the theoretical estimations. The reason is

obviously to be found in the fact that the tech-

nology is not mature enough for it to be fully

Figure 14 All-in-one relationship

Figure 15 NO is responsible for all
services delivered to the users connected to it

SLS:

QoSa, QoSb, QoSc

QoSIPtot

Services

ABC

Service Provider A

(SP A)

Network operator (NO)

QoS

Service Provider B

(SP B)

= SLA

Service Provider C

(SP C)