Tutorials - ADSL > Understanding Contention. Tutorials & FAQs: ADSL: Understanding Contention This Tutorial no longer represents the way that ADSL and ADSL2 products are delivered by BT, but the detail remains of interest As people should be aware, the ADSL product line sold by PlusNet is a contended service of either 20:1 or 50:1. These are the only two contentions currently possible under the BT IPStream package, which PlusNet uses and as provided to them by BT. DataStream ADSL providers have far more control over the connection including contentions of 1:1.
People get very confused on what contention is and isn't, even those people that do know, can still be in the dark to many of the facts. Cold hard fact:The word Contention means to "To compete in order to win something". To extend that, it means that when you are using your ADSL connection, you are competing with other people, in order to gain certain aspects of the service. That is only a basic concept of contention, or at least the contention that ISPs report.
Internet Peering Knowledge Center. DNS Quick Check - Online DNS Report Tool - Enter the domain to test realtime, Test your DNS delegation, DNS Servers, Mail and Web Servers, Network Admins, Webmasters, Hosting. Iftop: display bandwidth usage on an interface. Iftop does for network usage what top(1) does for CPU usage. It listens to network traffic on a named interface and displays a table of current bandwidth usage by pairs of hosts.
Handy for answering the question "why is our ADSL link so slow? ". Requirements libpcap libcurses Download The latest stable version of iftop is 0.17. Download: iftop-0.17.tar.gz or iftop-1.0pre4.tar.gz. If you wish to be notified of new releases of iftop then please subscribe to the Freshmeat project, or the mailing list. Change log The change log for iftop is available here. Mailing list There is a mailing list for iftop. Patches and contributions Patches are always very welcome, and I try to give credit appropriately. Git repository The iftop source code is maintained in git: Screenshots Standard view, port display off, two lines per host pair Host names hidden, source port shown, one line per host pair = network traffic by service Hosted by:
Open Port Check Tool. List of device bandwidths. This is a list of device bit rates, or physical layer information rates, net bit rates, useful bit rates, peak bit rates or digital bandwidth capacity, at which digital interfaces of computer peripheral equipment and network devices can communicate over various kinds of buses and networks. Bar chart of common computer interface speeds The distinction can be arbitrary between a bus, (which is inside a box and usually relies on many parallel wires), and a communications network cable, (which is external, between boxes and rarely relies on more than four wires).
Many device interfaces or protocols (e.g., SATA, USB, SCSI, PCI and a few variants of Ethernet) are used both inside many-device boxes, such as a PC, and one-device-boxes, such as a hard drive enclosure. Accordingly, this page lists both the internal ribbon and external communications cable standards together in one sortable table. Factors limiting actual performance, criteria for real decisions[edit] Conventions[edit] Bandwidths[edit]