FTTH Terminal Box
Field Assembly connector
EPON system
Fiber Switch
SFP Transceiver
Media Converter
PDH Multiplexer
Optical Automatic Protect
PLC Splitter
Optical Circulator
Optical Isolator
Optical Switch
Patch Cord/Connector
Optical Adaptor
Optical Attenuator
Patch Panel
Fiber Optic Closure
In-door Terminal Box
Optical Distribution Frame
FTTH Drop Cable
Optical Cable

°ŰWeb Switches
In enterprise networks, the name of the game is getting packets form point A to point B fast. By speeding IP packet forwarding, conventional layer3 and layer 4 switches have greatly improved network performance. But businesses such as Web and content hosting, and electronic commerce services, depend on fast, reliable, error-free Web performance.
Enter a technique called Web switching, Web switching is designed to address the requirements of Web traffic, Web switches intercept all traffic destined for a particular site .As a result, these switches have the ability to content requests and predict heavy traffic loads before servers before servers become overwhelmed.
Armed with URL load-balancing capabilities, Network Address Translation, and embedded Domain Name System intelligence, the switches use complex policies to manage and speed Web traffic flow.
Web switches are able to quicken the pace of Web traffic because they use URLs, in addition to IP addresses, to make switching decisions .URLs provide a method of identifying only the content requested; it does not dictate where are content might be found. So instead of viewing the IP address associated with the URL as the network address, this address points to the virtual IP address(VIP) of the Web switch, which functions as a cache or content traffic manage, The result; a consistently positive performance for Web site users.
Current load-balancing servers or devices, including Layer 4 switches, route incoming packets based on the destination IP address or the combination of destination IP address, protocol ID and transport port number. This can be problematic in a Web environment. To a layer 4 load-balancing device, web applications appear to be using TCP port 80-the typical TCP port for HTTP traffic-making Web application traffic indistinguishable form HTTP traffic.
Port numbers are a staple of TCP/IP communications. Because several application programs may be running on one machine and using a single network interface, TCP needs to keep track of what data goes to which program. This is done by assigning a port number to every TCP connection. Each TCP session has a destination port number in the TCP header. When a TCP segment is received, the TCP router knows which port to pass it to by looking at the port number in the TCP header. Some standard port unmbers are: Telnet, port23;Simple mail transfer protocol Mail,Port25;and Post Office Protocol 3 Mail, port 110.
Typically with Layer 4 switching, a Common Gateway Interface request looks no different than a Web-enabled SAP application or streaming audio request, even though all of these requests have very different quality of service (QoS) requirements.
In contrast, Web switches use URLs to route incoming TCP or User Datagram Protocol£®UDP£©flows to targeted servers. By looking into the HTTP payload down to the URL and cookie, a Web switch knows what content is being requested. With this knowledge, user-defined and/or pre-set policies determine which flow-security rules are enforced, which content is allowed or denied, and which QoS requirements are needed for specific content or users.
Web switches also dynamically replicate hot content to a Web cache and bring the cache into the load-balancing rotation, ensuring that users get the information they need no matter how much traffic is traversing the site.
bc-optics (hk) limited copyright © 2006. all right reserved    design by sendnet.inc