154 ITG engineering guidelines
The Media Card 32-port and ITG-Pentium 24-port trunk cards have two
Ethernet ports per card, so the IP Trunk3.01 (and later) system can suppor t
two different TLAN and ELAN subnet connections. The advantages of this
setup are as follows:
•to optimize VoIPperformance on the TLAN subnet by segregating it
from ELAN subnet traffic and connecting the TLAN subnet as close as
possible to the WAN router
•to make the amount of traffic on the TLAN subnet more predictable
for QoS engineering
•to optimize ELAN subnet performance (for example,for Symposium Call
Center Server (SCCS) and CallPilot functional signaling) by segregating
the ELAN subnet from TLAN subnet voice traffic
•to enhance network access security by allowing the modem router to be
placed on the ELAN subnet, which can be isolated from the customer’s
network or have access to/from theTLAN subnet only through a firewall
router
When using separate subnets as recommended, the Network Activity
LEDs provide valuable maintenance information for the Ethernet voice
interface. When using an ITG-Pentium 24-port trunk card in a single subnet
configuration, all traffic uses the ELAN subnet. This eliminates the use of
the TLAN (voice) network interface.
Subnet configurations
The following restrictions apply:
•The Leader 0 and Leader 1 cards must co-reside on a single TLAN
subnet with the Node IP Address.
•Follower cards can reside on separate TLAN subnets.
•All IP trunk cards belonging to the same node must co-reside on the
same ELAN subnet.
For dual subnet configuration, make sure the TLAN and ELAN subnets
do not overlap.
Example 1
Invalid configuration
The following configuration is not valid,as the TLAN and ELAN subnets
overlap.
ELAN IP 10.0.0.136
ELAN GW 10.0.0.129
ELAN Subnet Mask 255.255.255.224
Nortel Communication Server 1000
IP TrunkFundamentals
NN43001-563 02.01 Standard
Release 5.5 21 December 2007
Copyright© 2007, Nor tel Networks
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