Details

Autor(en) / Beteiligte

• Csaszar, Andras
• Takacs, Attila
• Szabo, Robert
• Henk, Tamas

Titel

Resilient reduced-state resource reservation

Ist Teil von

• Journal of communications and networks, 2005-12, Vol.7 (4), p.509-524

Ort / Verlag

Séoul: Editorial Department of Journal of Communications and Networks

Erscheinungsjahr

2005

Quelle

IEEE Electronic Library (IEL)

Beschreibungen/Notizen

• Due to the strict requirements of emerging applications, per-flow admission control is gaining increasing importance. One way to implement per-flow admission control is using an on-path resource reservation protocol, where the admission decision is made hop-by-hop after a new flow request arrives at the network boundary. The next-steps in signaling (NSIS) working group of the Internet engineering task force (IETF) is standardising such an on-path signaling protocol. One of the reservation methods considered by NSIS is reduced-state mode, which, suiting the differentiated service (DiffServ) concept, only allows per-class states in interior nodes of a domain. Although there are clear benefits of not dealing with per-flow states in interior nodes - like scalability and low complexity -, without per-flow states the handling of re-routed flows, e.g., after a failure, is a demanding and highly non-trivial task. To be applied in carrier-grade networks, the protocol needs to be resilient in this situation. In this article, we will explain the consequences of a route failover to resource reservation protocols: Severe congestion and incorrect admission decisions due to outdated reservation states. We will set requirements that handling solutions need to fulfill, and we propose extensions to reduced-state protocols accordingly. We show with a set of simulated scenarios that with the given solutions reduced-state protocols can handle re-routed flows practically as fast and robust as stateful protocols.