N O V A T E L W I R E L E S S T E C H N O L O G I E S L T D .
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A T C o m m a n d S p e c i f i c a t i o n - E x p e d i t e a n d M e r l i n
W i r e l e s s I P M o d e m s
Internal Stack Description
IP (Internet Protocol) is the basic network protocol that routes packets on an IP network. CDPD networks
and the Internet are IP networks. Transport protocols deliver packets between applications. Transport
protocols use the IP service to deliver data packets between network devices.
In order for an application to communicate across a network, it will first open a port on the local device.
The IP address of the local device and this port number becomes the unique address for this application,
and is sometimes referred to as a socket. When the local application communicates with a distant
application, it will send a packet addressed to the IP address and port number of that remote application.
This address is the destination address of the packet. The packet will also contain the source address, the
IP address and port number of the local application. The remote application may use the source address
of the packet received to communicate back to the local application.
There are two common transport protocols used in TCP/IP networks:
