Nortel BCM 3.7, Manual

Page: 668 / 1004

668 Configuring LAN resources
N0008589 3.3
Configuring LAN resources
The following section describes how to set up the LAN card on your Business Communications
Manager.
The information in this section includes:
• “Setting LAN global parameters” on page 668
• “Configuring a LAN interface” on page 669
• “Configuring multiple IP addresses for the LAN interface” on page 671
• “Viewing LAN performance” on page 672
Setting LAN global parameters
To set the LAN global parameters:
1 On the navigation tree, click the Resources key and click the LAN heading.
The Lan Parameters screen appears.
2 Set your global LAN parameters according to the information in the following table.
Table 171 LAN global parameters
Attribute Description
Fast Routing
(Between LANs
)
Allows you to enable or disable fast routing to improve LAN-to-LAN routing performance. This
feature is for a Business Communications Manager system equipped with two LAN cards. At
the same link speed, a smaller packet size means more packets to forward. Use a lower traffic
threshold. Permitted values:
Enabled or Disabled
Default: Disabled
Note : Do not use Fast Routing on systems that use NAT, IP Firewall Filters, IPSec tunnels, or
Quality of Service (QoS). Fast Routing bypasses these features and will cause the packets to
be routed incorrectly.
Decrement TTL When Fast Routing is enabled, Decrement TTL lets you decrement the time-to-live (TTL) value
in the IP header of packets as they travel from LAN to LAN. Decrement TTL lets you increase
processing time for each fast-routed IP packet, which reduces CPU cycles. This feature is used
when other routers or special applications on the network connect to the LAN interfaces.
Permitted Values:
Enabled or Disabled
Default: Disabled
Traffic Smoothing
(In Mbps) Lets you set the rate, in Mbps, at which the LAN driver receives packets from the LAN interface.
The main purpose of this feature is to limit the number of host CPU cycles spent on
LAN-to-WAN packet forwarding. Normally, LAN drivers operate at link speed, which implies that
the driver forwards packets as fast as possible until there is no packet in the receiving buffer.
Permitted values:
5 , 10 , 15 , 20 , 25 , 30 , 35 , 40 , 45 , 50, Disabled
Default: 10
Table 172 Guidelines to configure LAN to LAN traffic smoothing
64 bytes 128 bytes 256 bytes 512 bytes 1024 bytes 1500 bytes
Fast Routing enabled
Not needed Not needed Not needed Not needed Not needed Not needed
Fast Routing disabled
or LAN-to-WAN routing
20 mbps 30 mbps 50 mbps 50 mbps Not needed Not needed