Probe-based end-to-end overload control for networks of SIP servers

The Session Initiation Protocol (SIP) has been adopted by the IETF as the control protocol for creating, modifying and terminating multimedia sessions. Overload occurs in SIP networks when SIP servers have insufficient resources to handle received messages. Under overload, SIP networks may suffer from congestion collapse due to current ineffective SIP overload control mechanisms. This paper introduces a probe-based end-to-end overload control (PEOC) mechanism, which is deployed at the edge servers of SIP networks and is easy to implement. By probing the SIP network with SIP messages, PEOC estimates the network load and controls the traffic admitted to the network according to the estimated load. Theoretic analysis and extensive simulations verify that PEOC can keep high throughput for SIP networks even when the offered load exceeds the capacity of the network. Besides, it can respond quickly to the sudden variations of the offered load and achieve good fairness

A distributed end-to-end overload control mechanism for networks of SIP servers.

The Session Initiation Protocol (SIP) is an application-layer control protocol standardized by the IETF for creating, modifying and terminating multimedia sessions. With the increasing use of SIP in large deployments, the current SIP design cannot handle overload effectively, which may cause SIP networks to suffer from congestion collapse under heavy offered load. This paper introduces a distributed end-to-end overload control (DEOC) mechanism, which is deployed at the edge servers of SIP networks and is easy to implement. By applying overload control closest to the source of traf?c, DEOC can keep high throughput for SIP networks even when the offered load exceeds the capacity of the network. Besides, it responds quickly to the sudden variations of the offered load and achieves good fairness. Theoretic analysis and extensive simulations verify that DEOC is effective in controlling overload of SIP networks

Hysteretic Control Technique for Overload Problem Solution in Network of SIP Servers

This paper contains research and development results concerning application of hysteretic control principles to solve SIP servers overload problem, which is known from a number of IETF standards and scientific papers published over the past few years. The problem is that SIP protocol, being the application layer protocol, by default has no build-in means of overload control, as, for example, SS7, MTP2 and MTP3 protocols. It was the SS7 network, where a threshold mechanism of hysteretic signalling load control was first implemented. In this paper we describe the main up-to-date solutions of an overload control problem in a signalling network, and develop analytical models of hysteretic control, which are useful in the development of load management functions of SIP servers. We also propose the design of Open SIP signalling Node (OSN) software architecture which is intended to be used for simulations and comparison of various overload control mechanisms

Dynamic Scaling of Virtualized, Distributed Service Chains: A Case Study of IMS

Special issue on Emerging Technologies in Software-driven Communicationpostprin

A Secured Load Mitigation and Distribution Scheme for Securing SIP Server

Managing the performance of the Session Initiation Protocol (SIP) server under heavy load conditions is a critical task in a Voice over Internet Protocol (VoIP) network. In this paper, a two-tier model is proposed for the security, load mitigation, and distribution issues of the SIP server. In the first tier, the proposed handler segregates and drops the malicious traffic. The second tier provides a uniform load of distribution, using the least session termination time (LSTT) algorithm. Besides, the mean session termination time is minimized by reducing the waiting time of the SIP messages. Efficiency of the LSTT algorithm is evaluated through the experimental test bed by considering with and without a handler. The experimental results establish that the proposed two-tier model improves the throughput and the CPU utilization. It also reduces the response time and error rate while preserving the quality of multimedia session delivery. This two-tier model provides robust security, dynamic load distribution, appropriate server selection, and session synchronization

A Study over Registration Server System Simulation

This paper is a continuous study of the registration server system using a previous created real-time simulation application for my working product- T-Mobile Digits’ registration server system - an Enterprise-level solution ensembles Skype for Business, but with a sizable testing user pool. As a standard system design normally includes the hardware infrastructure, computational logics and its own assigned rules/configures, and as all the complex system, a well-set server structure is the kernel for no matter testing or commercial purpose. The challenges are real and crucial for both business success besides the concerns of access capability and security. It will begin with the discussion of the server-side architecture and the current functional workflows. However, the problematic project is facing stalling issues of the registration system whenever the automation tests deploys, or the pressure tests are happening. The project norms are based on my previous study, current study after architecture refactor and enterprise server function reporting tool: Splunk. I will create a new hypothesis of the mathematical model/formula towards the new architecture and will retrieve the most of simulation skeleton formed from last semester by introducing new variables and new model for the performance comparisons. This project will finalize the study from the last semester and evaluate the server performance under the new architecture. Also, I will try to explore and compare the performances before and after the structure level refactors in the server architecture design, which is in achieving to provide comparison to the system architects or other stakeholders and help them to explore the possible improvements of the current registration server system. The ultimate goal of the study remains the same: I am seeking opportunities to analyze over current problematic flows and achieving making betterments to the product and I expect to make theoretical suggestions to better for the current workflow and logic structure of the current registration server system so that the server would be more durable for automation tests and malicious attacks