3Com 3C10402B, Руководство администратора

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Special Issues 483
gateway. This occurs because the ConneXtions software makes H.323
ports look like hardware line cards to a Call Processor.
To emulate a group of simulated line cards, the gateway system must
read the destination address of every frame that is presented to its
Network Interface Card, instead of responding to only one hard-coded
Ethernet address. The gateway system is able to examine every Ethernet
frame because its NIC does not discriminate between frames. The NIC
passes every frame that it sees to the software for address evaluation.
To reduce the load on an H.323 gateway, you can connect it to an
existing multi-port switch. For optimum performance, use switches that
support 802.1(p and q). The 802.1(p and q) standard offers priority
enhancement which NBX systems exploit. Most 3Com switches support
this feature.
Remote Access Business people who travel can make routine calls without long distance
line charges by using an internet-ready laptop with Microsoft NetMeeting
to make H.323 calls, and a Virtual Private Network (VPN) connection to
the NBX system LAN. Microsoft NetMeeting software works with
Windows 2000 and it can be downloaded for free from
www.microsoft.com.
You can use Microsoft’s VPN Dial Up Networking (version 1.3) to establish
a virtual private network connection between a roaming laptop and the
NBX system LAN. One end of the VPN connection is in the laptop while
the other end must be located in a VPN server between the router and
firewall.
The VPN server provides caller authentication and a secure (encrypted)
channel across the internet. After a caller has been authenticated, the
connection is passed to the firewall, which sees the VPN connection as
coming from a recognizable (and therefore firewall-configurable)
IP address. VPN allows a business person to establish an IP connection
into the NBX LAN from a hotel room with internet service.
After an Internet connection has been established, change your
automatic call forwarding number:
1 Log on to NetSet as a user.
2 On the User Information tab, click Call Forward .
3 Click the telephone number radio button.