The adaptive load service (ALS): an ABR-like service for the Internet

Abstract

In this paper, we present a novel approach for realizing adaptive QoS control in the Internet called the adaptive load service (ALS). ALS was designed in a similar fashion to the available bit rate service (ABR) proposed for ATM. That is, the senders transmit control messages indicating their requirements, intermediate routers adjust the indicated values in accordance with their available resources and the receivers send the contents of the control messages back to the senders. The transmission behavior of the senders is then adjusted in accordance with the indicated values in the returned control messages. Unlike ABR, ALS is IP-based and was designed to scale for large multicast groups and accommodate the needs of heterogeneous receivers through the integration of sender-based and receiver-based adaptation mechanisms in addition to relying on the network feedback for adjusting the transmission behavior.Performance tests of ALS under different simulation topologies show its efficiency in terms of bandwidth utilization and loss reduction. The tests also show ALS to be fair towards competing TCP connections. Additionally, even though ALS uses a simple algorithm for determining the fair bandwidth share a connection should be using, ALS manages to fairly distribute available resources in accordance with the max-min fairness criterion.

Router Aided Congestion Avoidance with Scalable Performance Signaling

“…Actual ABR-like signaling based on RTCP is used with perflow state in the "Adaptive Load Service" (ALS) [13] and with a window-based approach, no per-flow state but somewhat strenuous router calculations where the header of every payload packet is examined in XCP [15]. In [14] and [16], the focus is on the interaction between ABR-like signaling and DiffServ.…”

Effective control for ABR multipoint-to-multipoint services

“…However, its congestion controlled traffi c characteris tic makes it an attractive service for use in high-performance IP networks as well, in order to promote fairness towards connec tions using TCP, the dominant Internet transport protocol [16]. In fact, Sisalem and Schulzrinne have proposed an ABR-like service for the Internet called Adaptive Load Service (ALS) whose traffic control mechanism is similar to that of ABR [16]. Although the mp-mp ABR fl ow control scheme we propose in this paper is im plemented for ATM networks, its design is applicable to various networks that support rate-based feedback control.…”