Cut-through Schemes Research Articles

Content Routing and Lookup Schemes Using Global Bloom Filter for Content-Delivery-as-a-Service

The dramatic growth of user-generated contents (UGCs) transforms the digital media value chain, and stresses current content distribution network (CDN). In order to deliver UGCs in an efficient and economical fashion, we have proposed content-delivery-as-a-service (CoDaaS) by leveraging cloud computing technology. However, due to the exponential increase of Internet traffic (especially the UGCs), traditional hashing-based content routing and lookup scheme in CDNs suffers from high delay and consequent inefficient delivery. This paper introduces a global compressed counting BF (CCBF) into CoDaaS to address this issue. By equipping it with the global CCBF, our system is able to check early on for the existence of any specific content among all the peering surrogates, before any local checking on each cache node. Based on this global CCBF, we propose two content routing and lookup mechanisms (i.e., parallel and cut-through schemes) to reduce the delay for better user experience. The comparative performance of those approaches is verified via both mathematical modeling and experimental simulation. The results show that for light traffic load, the average response time can be saved by up to 65.2% compared with traditional methods. In addition, the impacts and overheads of different synchronization schemes are also quantified to provide valuable insight for further optimizations.

A refined cut-through buffer management scheme for layered protocol stacks

Avoiding recopying of user data as it is passed between protocol layers helps break the protocol-execution bottleneck. The authors use a use a simple pointer-variable updating technique in the sending phase of their refined buffer cut-through scheme. Binary tree traversal is not required. Time is saved in allocating (and later deallocating) buffers for storing usually short data transfer protocol headers. Their scheme saves working buffer space for segmenting and linking of protocol data units. Because a simple linked list is constructed in the receiving phase, significant working buffer space can be saved. Each node of the linked list points to a user data segment. During the linked-list traversal, user data is copied directly to the user process when a node is visited. >

A comparison of three switching schemes in isotropic networks with noisy channels

Previous work on analyzing three switching schemes for isotropic networks, namely single hop and two cut-through communication schemes (with and without error checking by intermediate nodes), is extended. Each scheme is modeled by a discrete Markov chain. It is shown how the performance of the communication schemes depends on path length (n), load on the network ( lambda ), and the error rate (p). As expected, the cut-through schemes perform much better than the single hop when the communication load is light, but as the load increases, the cut-through schemes deteriorate more rapidly, until they are comparable. In fact, when the load approaches saturation ( lambda is close to 1-p), the cut-through schemes are actually worse than the single-hop schemes. The schemes with checking always outperform those without, but each node must perform more work in checking the correctness of the packets passing through. The time delay becomes infinite when the throughput approaches 1-p. The solutions are expressed as simple formulas and/or algorithms for each scheme. >