Support for Multi-Domain Services
Within GÉANT2, a best-of-breed approach to end-to-end service provision is being developed. Representatives of the NRENs that will be connected to GÉANT2 are working with DANTE to develop a number of production-quality tools for enabling users to receive a premium service, and to provide a helpdesk designed to identify and resolve network performance issues.
The activity dedicated to provision of support for multi-domain services is divided into three main areas of work:
- Provisioning is a core focus. This area of activity is developing the Advance Multi-domain Provisioning System (AMPS). This system, operating in a distributed manner, will manage the whole provisioning process, from user request through to the configuration of the appropriate network elements. AMPS version 1 was released at the end of 2005. In its initial form, actual router configuration must be performed manually, with the lead-time to reserve bandwidth measured in days. In time, however, AMPS will be able to automatically configure network elements, with a potential reduction in lead-time to minutes.
- In close collaboration with the Performance Measurement research activity, the end-to-end service initiative will implement a measurement system, to demonstrate that its service is being delivered to the required targets. Although this will initially involve the implementation of a single system, eventually a multi-domain approach is envisaged, which will allow individual networks to choose what tools they deploy.
- Finally, this activity will incorporate measures to provide direct support to deal with performance issues. The Performance Enhancement and Response Team (PERT), which began during the lifetime of the GÉANT network, provides support to users to resolve end-to-end performance issues.
The first multi-domain guaranteed service planned for GÉANT2 will be Premium IP (PIP). To have Europe-wide, true PIP, all connected NRENs would have to commit to and implement the DiffServ model. However, a network which does not implement DiffServ can still take part in PIP QoS if it meets the following criteria:
- Its capacity is significantly over-provisioned
- It forwards IP packets without changing the DSCP field in the packet header
- It correctly deploys the provisioning system designed by the multi-domain service support initiative.
IP technology as it is commonly used does not cater for those with exacting traffic requirements, such as low packet loss or low jitter. In future, new technologies will need to be introduced both at the level of networking protocols and of optical transmission techniques. The multi-domain service support activity therefore has strong links with each of GEANT2’s research activities, as it looks to take the concepts and techniques developed by those activities further into production-quality service.
In particular, it is working closely with the Bandwidth on Demand activity, which is also investigating methods of providing a guaranteed-bandwidth service across more than one network. The two activities differ in their technology focus, with the multi-domain service support activity focusing initially on routed Premium IP. Service sophistication also differs: the multi-domain service support activity will provide a basic service early on in the life of GÉANT2, while the BoD activity will deliver a more comprehensive, higher-quality service as the equipment and techniques become available.
