At this point we have looked at Q.922, the Frame Relay data-link interface.
We have seen how multiprotocol user data is encoded and exchanged in a
Frame Relay network. In the next section we will see how the Frame Relay
link and each PVC is activated (or deactivated) and how the status of each
link and the associated PVCs is maintained. These are all aspects of the LMI
(Local Management Interface). We will look at an optional extension to the
LMI for handling LAN-originated multicast/broadcast frames. Additionally,
we will briefly discuss Internet RFC 1293 (Inverse ARP) and issues related to
address resolution.
Local Management Interface
Local Management Interface is the phrase used in the FRF’s “Frame Relay
Specification” to describe the mechanisms for providing a user device with
network configuration and status information. Both ANSI T1.617 Annex D
and CCITT Q.933 Annex A have the same capability for providing configura-
tion and status information for PVCs as the LMI has. These three standards
are collectively referred to here as LMI unless otherwise indicated. It should
be noted that HP routers do not yet support CCITT Q.933 Annex A.
LMI procedures include:
Notification of the addition or deletion of a PVC.
Notification of the availability of a PVC.
Link integrity verification (keep alive).
PVC Status Messages
There are two defined LMI message types: Status and Status Enquiry. The
Status message is always sent to the attached router by the network in
response to a Status Enquiry message. A Status Enquiry message is sent by a
router at a predetermined polling interval to request status from the network.
Linking Up with Frame Relay
Local Management Interface
3-96
Содержание 600 Series
Страница 1: ...Hewlett Packard Series 200 400 and 600 Routers HP Routing Services and Applications ...
Страница 4: ......
Страница 5: ...1 Product Notes ...
Страница 6: ...Features of HP Routers Architecture and Technology Branch Office Routing Product Notes 1 2 ...
Страница 38: ...Architecture and Technology Software Control Path Architecture 1 34 ...
Страница 52: ...Branch Office Routing Future Directions 1 48 ...
Страница 53: ...2 Routing Services Notes ...
Страница 106: ...Bridging Service Traffic Prioritization 2 54 ...
Страница 158: ...Novell IPX Routing Service NetBIOS Protocol Support 2 106 ...
Страница 194: ...Data Compression for WAN Links Conclusion 2 142 ...
Страница 195: ...3 Application Notes and Case Studies ...
Страница 224: ...Improving Network Availability Application Recovery 3 30 ...
Страница 234: ...ISDN Wide Area Network Design Dry Creek Joint Elem School District Performance 3 40 ...
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