Glossary; Arp (Address Resolution Protocol); Clients And Servers; Firmware - ICP DAS USA PDS-220F Series User Manual

Glossary

1. ARP (Address Resolution Protocol)

Consider two machines, A and B, that share a physical network. Each has an assigned
IP address, IP
low-level software that hides MAC addresses and allows higher-level programs to
work only with the IP addresses. Ultimately, however, communication must be carried
out by the physical networks using whatever MAC address scheme the hardware
supplies.
Suppose machine A wants to send a packet to machine B across a physical network to
which they are both attached, but A only has the Internet address for B, IP
question arises: how does A map that address to the MAC address for B, MAC
ARP provides a method of dynamically mapping a 32-bit IP address to the
corresponding 48-bit MAC address. The term dynamic is used since it happens
automatically and is normally not a concern for either the application user or the
system administrator.

2. Clients and Servers

The client-server paradigm uses the direction of initiation to categorize whether a
program is a client or server. In general, an application program that initiates peer-to-
peer communication is called a client. End users usually invoke client programs when
they use network services.
Most client programs consist of conventional application program development tools.
Each time a client program is executed; it contacts a server, sends a request and waits
for a response. When the response arrives, the client program continues processing.
Client programs are often easier to develop than servers, and usually require no special
system privileges to operate.
By comparison, a server is any program that waits for incoming requests from a client
program. The server receives a request from a client, performs the necessary
computation and returns the result to the client.

3. Firmware

Firmware is an alterable program located or stored in the semi-permanent storage area,
e.g., ROM, EEPROM, or Flash memory.
and IP , and a MAC address, MAC
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