Analysing EtherChannel
September 2001
Fieldbus & Industrial Networking
In today's networks, bandwidth has become the primary focus of IT managers as they try to plan for the current and future needs of users. The availability of information and deployment of video technology over both the Internet and the company intranet have created problems with bandwidth. This increased traffic is typically seen on the backbone of networks that also carry mission-critical programs. Creating a dedicated path between mission-critical machines and end stations/users is often not an option. As a result, IT managers are faced with solving this problem with a minimal amount of money, using current equipment and current cabling.
EtherChannel is an 803.3-based full-duplex technology that provides network managers with the ability to create fast, reliable, high-speed backbones using existing cabling and network device infrastructure. Groups of up to four full-duplex point-to-point links are joined to create a logical channel for both Fast Ethernet and Gigabit technologies. For Fast Ethernet, Fast EtherChannel increments the channel speed by 200 Mbps per physical link, up to a total of 800 Mbps. For gigabit, Giga EtherChannel increments the channel speed by 2 Gbps per physical link, up to a total of 8 Gbps.
EtherChannel links can be established between the bridge ports of a bridge, the router interfaces of a router or the interfaces of a network server. These links are managed and load balanced by port aggregation protocol (PagP). PagP will automatically redirect and load-balance the remaining links if a link should fail. Besides bandwidth, this fault tolerance is one of the major benefits of EtherChannel.
Because EtherChannel is comprised of several links, the ability for complete monitoring, diagnosis and troubleshooting with synchronised time stamping across all links is impossible for most analysers on the market. WWG's DominoFast-Ethernet and DominoGigabit are not like most analysers. They have the common characteristics that are found in the Domino family of internetwork analysers:
* Stackable (up to 8) - up to eight Domino analysers can be stacked and controlled locally by one PC or remotely using DominoServer.
* Synchronised time stamps - all the Domino analysers in a stack have synchronised time stamps, so analysis can be performed across segments, devices and networks.
* Ability to monitor, capture, transmit and examine traffic - each Domino analyser has the ability to monitor traffic, providing statistics on the network; capture traffic for analysis; transmit frames to test the network health; and examine the traffic that was captured, or realtime as the frames enter the buffer.
* Common GUI - Domino analysers share the same GUI or 'look and feel', so users familiar with one topology have little trouble navigating and performing similar tasks in other topologies.
* Hardware and software filters - by having pre-capture (hardware) and post-capture (software) filters, the user can ensure that the data being captured concerns only the device(s) they are interested in.
* Post-Capture advanced search abilities - with Examine, a user can quickly set up a filter and search criteria by a few clicks of the mouse button or they can do complex Boolean searches.
Wavetek Wandel Goltermann
(011) 266 1817
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