Abstract: Methods, systems, and apparatus guarantee bandwidth for a network transaction. A network is logically organized as a tree having a plurality of nodes. Each node can guarantee service for a network transaction through the network. Each node monitors its traffic and reserves predefined amounts of unused bandwidth with its adjacent node. If a particular node needs additional bandwidth, that node borrows the bandwidth from its adjacent node.

Abstract: An improved signal plug used in communication devices, which includes a case, a cover, and a holding groove at the center of the case. The holding groove extends to the back edge of the case, and it has multi-grooved holes on the front end. Cores of the signal cable can be pulled out from the grooved holes on the front end of the case when they are inserted into the case, in order to embed the signal cable in the back opening and the holding grooves of the case to relatively increase the length of exposed twisted cores, to improve the overall signal quality in transmission.