Skype - 3.0 beta Guide de l'utilisateur télécharger pdf (Page 10)

Skype Network Administrator’s Guide Skype 3.0 Beta 10

2006-10-31 Document version 2.0 Beta

The computing resources required to support the activities of a supernode or relay host are

small compared with relative processing power, memory, storage space, and available

bandwidth on a given computer.

In addition, given the strict bandwidth limits placed on supernodes and relay hosts, Skype

end users cannot tell the difference between a given computer being used as a regular

Skype node, supernode, or relay host because the capabilities required to support the

additional functionality are transparent and have no noticeable impact on a given

computer’s performance.

Skype Client / Supernode Relationship

Every Skype client stores a list of supernode network addresses that allow a peer node to

connect with the network. When a Skype client successfully contacts a working supernode,

the Skype client gets an updated list of network addresses of currently active supernodes

for future use.

The Skype client selects an active supernode as its “upstream” link and then uploads search

requests and other relevant data to this supernode. This supernode, in turn communicates

with other supernodes to satisfy any search request. Search requests might be an

authorization, a voice or video call, IM, or a file-transfer request. Skype clients always first

attempt to communicate with other Skype clients directly.

When it is impossible for a given Skype client to communicate with another Skype client

directly, the active supernode routes the connection and call traffic through a relay host.

Each Skype client opens multiple standby connection paths and then dynamically chooses

the path with the lowest latency and optimal bandwidth to increase call-completion rates

and improve overall service quality. The Skype client then connects to a peer node and

transfers text, voice, file transfer data, and video using Hypertext Transfer Protocol

(HTTP).

The Skype client maintains multiple connections even if it’s not a supernode. As a result,

you may see a large number of TPC/UDP connections, even when a Skype client is not a

supernode or relay host.

Important Note: Certain inexpensive routers, firewalls, or gateways (generally designed

for home use and not certified by Skype) may fail to support the number of concurrent

TCP/UDP connections required to ensure high call completion rates and call quality.

Skype Global Index

Prior to Skype version 1.2, user Contact Lists were maintained in each individual’s Skype

client (on a given computer). A centralized directory for managing Contact Lists was

added at version 1.2 of the Skype client to ensure that users’ Contact Lists are available on

any computer when they log in to Skype.

This means that you can deploy new computers (or let users work from multiple

computers) while retaining access to Contacts Lists when the users are logged in.

More recently, the now decentralized directory service or global index was deployed to

enhance the overall quality of the end user experience. As mentioned previously, the

global index is not hosted on central servers and is, instead, maintained as a hierarchical

arrangement of all available supernodes.

1 2 ... 5 6 7 8 9 10 11 12 13 14 15 ... 36 37

Commentaires sur ces manuels

Pas de commentaire

Skype - 3.0 beta Guide de l'utilisateur Page 10

Commentaires sur ces manuels

Produits connexes et manuels pour Logiciel Skype - 3.0 beta