next up previous
Next: 4 Constructing self-regulating Network Up: Preventing Rather Repairing - Previous: 2 Tasks of Network

3 Resource Allocation and Network Management

 

Although the work of [8] already integrates performance management and admission control, existing equipment does not yet implement corresponding features. Most vendors just began with the release of signaling capable software and are far away from providing features regarding resource allocation adjustment.

Besides the future possibility to influence the admission control, one important point in this work is the renegotiation of the traffic contract for existing connections. Renegotiation is not standardized yet, although it's importance is obvious. It will not be possible to admit a single user to use a large part of the available resources, if the possibility to lessen his resources when contention occurs does not exist.

For public providers, renegotiation will be a sensitive point despite its usefulness. The possibility to get renegotiated must be agreed upon at establishment time and considered with appropriate tariffs. This aspect is considered in this work in the form of 'fairness policies' which have to specify restrictions regarding renegotiation. However, further considerations in this work will show that the potential expense to include renegotiation facilities in public service contracts is justified.

A further point to consider are available services in the network. Although several services are roughly specifiedgif, most vendors - especially in the LAN environment - implement their own set of services. These tend to be a 'best effort service' mostly comparable to ABR, and a guaranteed service, which means that a certain peak rate is guaranteed (compare switches from Cisco Systems and Fore Systems ). Other vendors (for example GDCgif) provide multiple VBR Services with different quality assurances and a CBR service. In any case it is possible -- and done so in this work for generality -- to map the different services on requests for a certain mean rate and peak rate, where only the mean rate is usually guaranteed.

Another important point in this work is the restriction of the resource allocation area to bandwidth allocation questions. The inclusion of requirements regarding cell delay has not been considered so far. The integration should thus be possible, when following the thread of the next section.



next up previous
Next: 4 Constructing self-regulating Network Up: Preventing Rather Repairing - Previous: 2 Tasks of Network



Anja Schuhknecht
Wed May 31 09:56:07 MET DST 1995