Recently in Circuits Category

I just spent 2 and a half hours on the phone today bring up a new circuit, one important point I learned was about LMI or Local Management Interface.

My router was configured for

frame-relay lmi-type ansi


but the carrier was looking for lmi of type 'cisco'. So they weren't exchanging lmi properly.

Loging on to my Visual UpTime Select Multiprotocol T1 CSU DROP & INSERT ASE I saw this:

The ASE is sending LMI requests and the switch is responding.
2 frame relay circuits were reported.
All circuits are ACTIVE.


There are three standards for LMI:

1. ANSI's Annex D standard, T1.617


2. ITU-T's Q.933 Annex A standard


3. the "Gang of Four" standard, named for the four companies that developed it: Cisco, DEC, StrataCom and NorTel (Northern Telecom).

Frame Relay Configuration and Management

Frame relay is described as an encapsulation method and is directed mainly to users with large T1 network installations. Cisco supports the two generally implemented specifications for frame relay Logical Management Interfaces (LMIs):

• The Frame Relay Interface specification produced by Northern Telecom, Digital Equipment Corporation, StrataCom, and Cisco Systems.
• The ANSI-adopted frame relay specification,T1.617 Annex D.

Cisco's implementation also conforms to the Link Access Procedure (LAP-D) defined by the CCITT under its I-series (ISDN) recommendation as I122, "Framework for Additional Packet Model Bearer Services."

at the end after they change to ansi on the lmi, the circuit was up:


FRAME

Link Statistics
Near Octets: 15948 Far Octets: 69996
Near Frames: 489 Far Frames: 405
Near Frame Errors: 3 Far Frame Errors: 1
Near Aborted Frames: 0 Far Aborted Frames: 0
Near Short Frames: 0 Far Short Frames: 43
Near Long Frames: 0 Far Long Frames: 0
Current Utilization: 0.01 Current Utilization: 0.01
Maximum Utilization: 0.50 Maximum Utilization: 27.43
Current Frames/sec: 1 Current Frames/sec: 1
Maximum Frames/sec: 6 Maximum Frames/sec: 48
Drop Events: 0
Link State: Up
Port Unavailable Secs: 242
Frame Relay LMI is working correctly.
1 frame relay circuits were reported.
All circuits are ACTIVE.


So if you ever are having problems turning up a T1 make sure you have LMI specified the same on the carrier side and on your router!