ZyXEL Communications MSC1000G Series, Руководство пользователя

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Management Switch Card User’s Guide
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IMA Screens
This chapter describes how to configure settings related to the E1 ports on an IMA line card.
10.1 IMA Overview
Inverse Multiplexing for ATM (IMA) is a technology used to transmit ATM traffic over a bundle of T1
or E1 lines. The IMA line card supports up to 8 E1 ports for E1 connections. With the IMA line card
installed, the IES is able to connect both IP and ATM networks. See
IMA Application on page 44 .
10.2 What You Need to Know
IMA Group
An IMA group is a virtual link that combines one or multiple E1 lines in order to increase total
bandwidth for link. You must configure and enable at least one IMA group to use the IMA line card.
You must check the settings on the remote connected ADM (Add-Drop Multiplexing) device before
configuring an IMA group. In the IES device:
• you can configure up to 8 IMA groups for each IMA line card.
• you can configure up to 64 IMA groups in total on your IES device.
TLS and IMA Tagged PVC
Transparent LAN Service (also known as VLAN stacking or Q-in-Q) allows a service provider to
distinguish multiple customers VLANs. TLS adds an outer VLAN tag (S-tag) to the IEEE 802.1Q
tagged (C-tag) frames that enter the network. This allows a service provider to provide different
services, based on specific VLANs, for many different customers. Refer to
Section 9.2.12 on page
209 for more information.
To bridge untagged traffic through DTPVCs, the IMA line card removes S-tag and C-tag from frames
and converts them into ATM cells according to VLAN ID to PVC mappings. One combination of S-tag
and C-tag maps to one PVC. For example, if a service provider (
S1 ) has three customers ( C1~C3 ),
the service provider has to configure three DTPVCs on both local and remote IMA devices. The
VLAN ID to PVC mappings should be configured on the both IMA devices.