Allied Telesis OmniConnect/ISDN, Руководство пользователя

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OmniConnect / ISDN
User’s Manual Page 5
Part number 613-10787-00
2.1.8. DHCP server
DHCP automates IP addressing and reduces the number of IP addresses a site might require.
The OmniConnect can function as a dynamic host configuration protocol (DHCP) server.
When a DHCP server is enabled and configured, it assigns and manages IP addresses from a
specified address pool to DHCP clients. The options supported by this server are sufficient for
255 TCP/IP clients. If more IP addresses or options are required, a higher-capacity DHCP
server (i.e., Windows NT) could be used.
2.1.9. Network address translation
OmniConnect supports port or Network Address Translation (NAT) allowing a designated
private IP network to communicate with the outside world. When configured, OmniConnect
translates source addresses from an IP private network to a single, global, unique IP address
before forwarding the packets to the outside world. OmniConnect’s implementation of NAT
supports a variety of multimedia applications, games and standard utilities such as telnet, FTP
and HTTP by carefully monitoring each applications use of IP addresses and port numbers. In
addition, the OmniConnect/ISDN allows unsolicited UDP and TCP requests from the Internet
to be routed directly to a single client based solely on port number. This allows applications
that require conversations or connections to be initiated from the Internet such as Diablo,
Microsoft NetMeeting and CuSeeMe to operate correctly. In addition, the
OmniConnect/ISDN allows users to place web servers or email servers on the local LAN, by
allowing
holes in NAT. This allows users to access an internal web server that uses a globally
administered IP address from the Internet.
2.1.10. IP address assignment through IPCP
The access device can be assigned an IP address from the remote device using Internet
Protocol Control Protocol (IPCP) address negotiation. The implementation is based on
RFC1332. IPCP address negotiation is on by default in any profile configured for IP routing.
This feature does not support assigning addresses to remote devices.
2.1.11. Force dynamically negotiated IP addresses
When this feature is off, the negotiated IP address is assigned to the standard or the user-
defined address. It also tells the software to try any IP address configured for this port in
PPP’s IP address negotiation. When this feature is on and the internal profile does not contain
an address, the negotiated IP address is automatically assigned to the internal profile by the
system. If the Internal profile contains an address, it will be assigned to the user-defined
profile from which the call was initiated.
2.1.12. Data compression
The OmniConnect access device supports data compression using the compression algorithm
QIC-122 standard, Stac LZS. Data compression is a software configuration option that
optimizes the ISDN line bandwidth. Packets are compressed before being sent onto the ISDN
line. After they arrive at their destination, the packets are decompressed and sent on to the
remote LAN.
2.1.13. Flash firmware upgrade
The OmniConnect/ISDN remote access / access device, stores its firmware in FLASH read-
only memory (ROM). The FLASH ROM allows the OmniConnect/ISDN access device
firmware to be easily upgraded using the local serial console port. Firmware upgrades may be
downloaded from the OmniConnect web site at
http://www.alliedtelesyn.com . All current
configuration parameters for the OmniConnect/ISDN are stored in non-volatile storage. The
configuration parameters can be stored or retrieved via both the serial console port and the
OmniConnect configuration manager.