Robustness to inflated subscription in multicast congestion control

Abstract

Group subscription is a useful mechanism for multicast congestion control: RLM, RLC, FLID-DL, and WEBRC form a promising line of multi-group protocols where receivers provide no feedback to the sender but control congestion via group membership regulation. Unfortunately, the group subscription mechanism also offers receivers an opportunity to elicit self-beneficial bandwidth allocations. In particular, a misbehaving receiver can ignore guidelines for group subscription and choose an unfairly high subscription level in a multi-group multicast session. This poses a serious threat to fairness of bandwidth allocation. In this paper, we present the first solution for the problem of inflated subscription. Our design guards access to multicast groups with dynamic keys and consists of two independent components: DELTA (Distribution of ELigibility To Access) -a novel method for in-band distribution of group keys to receivers that are eligible to access the groups according to the congestion control protocol, and SIGMA (Secure Internet Group Management Architecture) -a generic architecture for key-based group access at edge routers.

Securing User-Controlled Routing Infrastructures

“…To detect high losses, we borrow the mechanism based on erasure codes proposed in [12]. FI node A associates a nonce a with every n consecutive packets forwarded via entry (id, * ) to next hop B.…”

“…Challenge-response protocols have been used for a long time in diverse areas. The idea of using erasure codes to ensure that uncooperative hosts do not oversubscribe to highbandwidth streams was proposed recently in the context of multicast [12]. Pushback has been proposed for rate-limiting the traffic of IP aggregates by Mahajan et al [20].…”

A Two-Time-Scale Design for Edge-Based Detection and Rectification of Uncooperative Flows

“…The Dual Algorithm consists of a static source update and a first order dynamic price update: (6) where the positive projection for a general function is defined as if , or and if and .…”

“…From (6), the unique equilibrium for the dual control law is obtained from the equations (7) if if (8) which, as shown in [1], correspond to the solution of the optimization problem (4), in which 's play the role of Lagrange multipliers for the capacity constraints. For the primal control law (5), the equilibrium obtained from (9) (10) approximates the optimality condition (7)- (8) with the help of the penalty functions .…”

“…With new software advancements, however, "uncooperative" users can change their congestion control schemes to gain more than their fair share of bandwidth, at the cost of cooperative users. This uncooperative behavior can lead to TCP unfriendliness, congestion collapse [3], [4] and, to a traffic-based denial-of-service to cooperative users [5], [6]. Detecting uncooperative users, and "rectifying" their flow rates to comply with cooperative rates, and thus, improving quality of service for individual flows becomes an important emerging problem in network management.…”