Scalable and Efficient Forwarding Table Design for Multi-Link Failover in OpenFlow-Enabled Networks

Abstract

One of the key technical challenges in 5G is to ensure a high level of end-to-end service availability and reliability. Software-defined networking leveraging on a centralized network-forwarding control and management paradigm is expected to fulfil such requirements and even enhance their capabilities, compared to the traditional reliability mechanisms in the legacy network. This paper presents an enhanced forwarding table design for scalable and efficient failover support on multilink failures in OpenFlow networks. The proposed forwarding table is designed with flow grouping and flow aggregation methods to achieve faster link failover and compress the flow rules for alternate paths against multi-link failures. To validate the proposed forwarding table design, we evaluate the performance in the following points: (1) how much resilience can be provided, (2) how many forwarding rules can be reduced to configure the alternate paths against multi-link failures and (3) how rapidly the failover can be achieved. Emulation results confirm that the proposed design reduces the number of disrupted flows and required forwarding rules to configure the alternate paths. We could also identify that it can achieve the recovery in 2-3 ms.

Performance analysis of handover delay and buffer capacity in mobile OpenFlow‐based networks

“…Modeling handover with shared buffer at the switch (model SFB) switch 1 (αT cp (2) , where T cp is the throughput of class CP); (3) we assume a totally synchronized system, meaning that immediately upon receiving the off-port message, switch 2 knows that an on-port message is received at class FP at switch 2, and this message is similarly forwarded from switch 2 to the controller (αT fp (3) ); (4) this packet is then processed by the controller and sent to inform both switch 1 and switch 2 about the change in the network (αT cp (4) );…”

“…Packet forwarded from switch 2 to controller (3) (x, y, z > 0) (x + 1, y, z − 1) (α + β)μ s Packet serviced from controller to switch 1 (4)…”

SDN‐based failure detection and recovery mechanism for 5G core networks

“…A network failure is defined as an unpredictive and forced temporary modification in the network that impacts the actual design of traffic and always results in capacity degradation of the affected links . There are several categories of network failures: Link failures : a link in the network fails; Node failures : there is a failure of a network equipment; Single failures : a single fault occurs at a time; Multiple failures : multiple faults occur nearly at the same time …”

“…• Single failures: a single fault occurs at a time 4 ; • Multiple failures: multiple faults occur nearly at the same time. 2 Network restoration procedures can be classified in several categories:…”

“…In an SDN environment, a link recovery can be achieved either by a restoration mechanism or a protection mechanism. 2 The restoration mechanism requests the SDNC to re-establish the connections after a failure detection. For mobile networks, where many flows may need to be recovered, it is very challenging to achieve fast recovery times.…”