Title:
Designing Enforceable Network Contracts
Designing Enforceable Network Contracts
Authors
Lychev, Robert
Feamster, Nick
Feamster, Nick
Authors
Advisors
Advisors
Associated Organizations
Collections
Supplementary to
Permanent Link
Abstract
Internet connectivity depends on contractual agreements between
cooperating entities, such as administrative domains
(AD), where an agreement over a certain level of service is
made. Contracts (e.g., SLAs) for providing certain levels of
service must be enforceable, and ADs must have an incentive
to meet their contractual obligations. Previous work has
designed mechanisms for both pricing and network accountability,
but no existing work examines contract structures
with respect to different accountability frameworks, and how
together they may affect an AD’s incentives to fulfill contracts.
We study how different contract structures—in particular,
path-based versus pairwise contracts—affect ADs’
incentives to establish contracts (which, in turn, can affect
overall connectivity) and, once contracts are established, to
forward traffic according accordingly.
This paper presents several contributions. First, we derive
sufficient conditions for path-based contract systems and accountability
frameworks for entities to have an incentive to
forward traffic according to their contracts, provided that all
parties involved are rational. Second, we show that for path-based
contracts at equilibrium where nodes are encouraged
to fulfill their contracts, only a constant amount of monitoring
is required for every participant to make a positive
profit; this is not the case for pairwise contracts. Third, we
show how systems that rely on pairwise contracts are prone
to depeering in presence of sufficient supply and demand
due to coarse granularity, a contractual failure that systems
which rely on path-based contracts are immune to. We propose
modifications to pairwise contracts that could prevent
such failures. Finally, we present situations of depeering that
may be unpreventable due to maliciously behaving parties
for both pairwise and path-based contract structures. For
such scenarios, we show that while path-based contracts allow
the sender of traffic to get reimbursed, this is not guaranteed
in pairwise contract systems.
Sponsor
Date Issued
2009
Extent
Resource Type
Text
Resource Subtype
Technical Report