Simulation of the SCTP Failover Mechanism
Some features of SCTP provide opportunities for creating redundancies for signalling over IP networks. This paper presents the behaviour of SCTP in failover scenarios, based on literature review and simulations. Simulations were carried out using NS2 in a multi-homing environment. It was found, as expected, that when failover took place, the undelivered chunks were retransmitted to the secondary path while new messages were still transmitted to the primary path until the error count was exceeded whereupon the primary path was declared inactive and a new primary path was chosen. The simulations raised some concerns regarding the duration of failover for different PRL values. *
On the Use of SCTP in Failover-Scenarios
The new general purpose transport protocol SCTP (Stream Control Transmission Protocol) has been developed for transport of signaling data, such as Signaling System No. 7 MTP level 2 or 3 user primitives, over IP networks. Since this application has especially high requirements towards the underlying transport protocol concerning reliability and fast recognition and recovery from failures, SCTP-based transmission must provide a high degree of network level fault tolerance. In our contribution we look at a typical link failure scenario in a multi-homed setup, and investigate two options for fast recovery from such an event, namely seamless SCTP switch-over, and a user level switch-over as has been suggested for the MTP Level 2 peer adaptation layer. Moreover, we will analyze necessary parameter settings for fast recovery from the failure situation. 1
Representation of systems disturbed by wide band noise
In this paper, a method of handling and working with wide band noise is developed. We represent wide band noise as a distributed delay of white noise and use it to reduce a nonlinear system disturbed by wide band noise to a nonlinear system disturbed by white noise. An application of this reduction to a nonlinear filtering problem under a wide band noise disturbance is discussed.