162GLOSSARY

proxy cache The Webcache is connected to a Layer 2 switch in your LAN. The Web browser on each client machine in your network must be configured to explicitly direct its Web requests to the Webcache.

router A router is a device on your network which is used to forward IP packets to a remote destination. An alternative name for a router is a gateway.

server A computer in a network that holds the master version of a web page/object. A web request that is not served by the Webcache must go to the server across the World Wide Web. This is termed a cache miss. A web request served by the Webcache is termed a cache hit.

SNMP Simple Network Management Protocol. The current IETF standard protocol for managing devices on an TCP/IP network.

subnet An IP network can be divided into sub-networks, also known as subnets. If you have a small network (less than 254 devices), you may decide not to have multiple subnets.

subnet mask A subnet mask is used to divide the device part of the IP address into two further parts. The first part identifies the subnet number. The second part identifies the device on that subnet.

TCP/IP Transmission Control Protocol/Internet Protocol. This is the name for two of the most well-known protocols developed for the interconnection of networks. Originally a UNIX standard, TCP/IP is now supported on almost all platforms, and is the protocol of the Internet.

TCP relates to the content of the data travelling through a network — ensuring that the information sent arrives in one piece when it reaches its destination. IP relates to the address of the client machine to which data is being sent, as well as the address of the destination network.

Telnet A TCP/IP application protocol that provides a virtual terminal service, letting a user log into another computer system and access a device as if the user were connected directly to the device.

trace route This feature allows you to display the network hops from the Webcache to a device on an IP network.

transparent cache The Webcache is connected to a Layer 4 device in your LAN which is capable of Redirection. The Layer 4 switch (also known as a Layer 4 redirector or Web enabled switch) automatically redirects all Web requests to the Webcache.