User Manual

Appendix E: Glossary
MTU
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Psion Teklogix 9160 Wireless Gateway User Manual
MTU
The Maximum Transmission Unit is the largest physical packet size, measured in
bytes, that a network can transmit. Any messages larger than the MTU are
fragmented into smaller packets before being sent.
Multicast
A Multicast sends the same message to a select group of recipients. Sending an e-
mail message to a mailing list is an example of multicasting. In wireless networks,
multicast usually refers to an interaction in which the access point sends data traffic
in the form of IEEE 802.1x Frames to a specified set of client stations (MAC
addresses) on the network.
Some wireless security modes distinguish between how unicast, multicast, and
broadcast frames are encrypted or whether they are encrypted.
See also Unicast and Broadcast.
N
NAT
Network Address Translation is an Internet standard that masks the internal IP
addresses being used in a LAN. A NAT server running on a gateway maintains a
translation table that maps all internal IP addresses in outbound requests to its own
address and converts all inbound requests to the correct internal host.
NAT serves three main purposes: it provides security by obscurity by hiding internal
IP addresses, enables the use of a wide range of internal IP addresses without fear of
conflict with the addresses used by other organizations, and it allows the use of a
single Internet connection.
Network Address
See IP Address.