Last update PvD

2.5 SML
Service Management Layer


  1. Customer/Provider relationship
  2. Views at SML

[M.3010] Service management is concerned with, and responsible for, the contractual aspects of services that are being provided to customers or available to potential new customers.
It has five principle roles:

In short:  Exploit services provided by the network to the customer (external view), i.e. the commercial aspects of network services.
Basically not so much interested in the network but for the consequences in the services experienced by customers.  Typically concerned with contractual aspects of services being provided.  SML should be able to answer customer requests/­complaints, and should therefore have some insight in the status of the network.
Preferably, SML should cover multiple services as the same customer is likely to have (contracts for) other services as well (e.g. Voice, Data, Leased Line), each with various 'Value Added Services' options.  Virtually it should be a single point of contact.

Customer / Provider relationship

Apparently, M.3010 defines that all interactions between a customer and a provider are at SML, whether it is the Customer/­Provider, or Provider/­Operator (other service providers) interface.

The TMN hierarchical layered model then looks like:

Physical view

There is no fixed role as customer or provider;  for extensive services an operator can not provide the full service all by himself and need to use services of other operators (Value Added, international, etc.), so he is than customer with the other operator (on behalf of his customer).

Note that a customer is not necessarily a true operator with his own network;  it can be some business who uses telecom extensively (i.e. using lots of ports in the provider's network, e.g. a VPN).  If it is an important customer, he may have special access to the provider's TMN to monitor and potentially control the resources he uses.  Such a special form of relationship is the so-called Customer Network Management (CNM):  the facility for a customer to control his resources in the network of an operator.
Note that M.3010 explicitly allows a Service Provider to connect to NML or EML of an Operator.  Of course this can be permitted by the Operator, and will typically depend on his relationship (i.e. trust) with the Provider and security facilities in Network Management in order to restrict the Provider.

The Customer/provider relationship (including domains, contracts, SLAs, CNM, etc.) is discussed in more detail in chapter Interworking.

Views at SML

At SML the view is from outside the network (black box view).  The view is per service type and/or customer (VPN):

Value Added Service view

For a particular customer the network is a block box;  only the interfaces (Service Access Points:  SAP) are visible for him:  the access points 'A', 'R' and 'Z', and the value added service 'Conference'.

Operations: (example)

Next section: BML
Up to Contents
Up to Index