Cisco 700 - Manual (Page 19)

Overview 1-5
Port Address Translation
Cisco 700 series routers support port address translation (PAT) allowing a designated
private IP network to communicate with the outside world. When configured, Cisco 700
series routers translate source addresses from an IP private network to a single, global,
unique IP address before forwarding the packets to the outside world.
IP Address Assignment Through IPCP
The router can be assigned an IP address from the remote device using Internet Protocol
Control Protocol (IPCP) address negotiation. The implementation is based on RFC 1332,
and it supports IPCP options 1 and 3. (It does not support option 2, TCP/IP Header
Compression.) IP unnumbered is also supported. IPCP address negotiation is on by default
in any profile configured for IP routing. This feature does not support address assignment
to remote devices.
Data Compression
Cisco 700 series routers support data compression using the compression algorithm
QIC-122 standard, Stacker LZS. Data compression is a software configuration option that
optimizes the ISDN line bandwidth. Packets are compressed before being sent to the ISDN
line. After they arrive at their destination, the packets are decompressed and sent to the
remote LAN.
Fee Pulse Mode
Fee Pulse Mode manages the ISDN connection based on the paid periods of time. If other
thresholds indicate a call should be dropped due to low traffic, Fee Pulse Mode maintains
the connection until the current paid period has expired. Therefore, you are not paying full
price for part of a connection period. This feature is available only for NET3 (same as
ETSI) switch types, and you must subscribe to Advice of Charge-During Active Call
(AOC-D) supplementary service.
If the feature is enabled and idle time expires, the router checks the remaining time in the
current paid period. The router maintains the connection until the end of the paid period,
minus the disconnect time required to terminate the PPP and ISDN links.