Multi-domain end-to-end Network Service Level Agreements

Vassiliki Pouli, Mary Grammatikou, Chrysostomos Tziouvaras and Vassilis Maglaris, Network Management & Optimal Design Lab. (NETMODE), Greece

In Grid environments whenever applications require specific service guarantees, specific mechanisms should be developed in order to guarantee the quality of service (QoS) required across interconnected network domains. These mechanisms can be facilitated through the use of Service Level Agreement (SLA) contracts between the involved parties to describe and enforce the necessary QoS levels for network service provisioning. SLAs could involve mulitple domains, with network services offered from individual network service providers across end-to-end paths. In this case, per-dmain SLAs need to be combined and offered as a whole to end-users.

In the EGEE project, distibuted resources and services are interconnected in a multi-domain network environment. To implement service quality contracts, they defined a network SLA establishment procedure along with network service provisioning. They then described the monitoring procedure needed to assure complience of service and network providers with the contracted level of QoS that applications expect along the path. Finally, in order to test the SLA installation and monitoring procedures they used a Grid application targeted at the remote control and monitoring of instrumentation resources with stringent levels of QoS (e.g. bandwidth, delay) across the interconnecting network(s). For this use-case they have tested the data transfer, comparing a DiffServ (Premium IP) enabled multi-domain end-to-end path as opposed to a Best-Effort one. For both cases, they evaluated SLA installation and monitoring by taking measurements over the network and cross-checking if the SLA guarantees are honored.