3com 3031 Instruccion De Instalación

C

HAPTER

 24: F

RAME

 R

ELAY

 C

ONFIGURATION

Perform the following configuration in Interface View.

The default type of LMI protocol of interface is Q933a.

Frame relay protocol parameters and their configuration are shown in Table 307 
and Table 308:

These parameters are stipulated by Q.933 Appendix A, with the meanings as 
follows:

Meanings of parameters related to DTE operating mode:

■

DTE sends a Status-Enquiry message at certain interval (determined by T391). 
There are two types of Status-Enquiry messages: link integrity verification 
message and link status enquiry message. Parameter N391 defines the ratio of 
the two types of messages sent, i.e. number of link integrity verification 
messages : number of link status enquiry messages = N391-1: 1

■

N392: it indicates the threshold for errors among the observed events.

■

N393: it indicates the total of observed events.

DTE sends a Status-Enquiry message at certain interval (determined by T391) to 
query the link status. DCE immediately sends a Status response after receiving the 
message. If the DTE does not receive any response within a specified time, it will 
record this error. If the error number exceeds the threshold, DTE will regard the 
physical channel and all virtual circuits as unavailable. N392 and N393 together 
define "error threshold". In other words, if errors reach N392 among the N393 
Status Enquiry messages sent by DTE, DTE will consider that error number has 
reached the threshold and the physical channel and all virtual circuits are 
unavailable.

Table 306   Configuring frame relay LMI protocol type

Configure frame relay LMI protocol type

Restore the frame relay LMI protocol type 
to the default value

Table 307   Frame relay protocol parameters

DTE

Request PVC status counter (N391)

1 to 255

6

Error threshold  (N392)

1 to 10

3

Event counter (N393)

1 to 10

4

User side polling timer (T391), the value 0 
indicates that LMI protocol is disabled

0 to 32767

(in seconds)

10

(in seconds)

DCE

Error threshold  (N392)

1 to 10

3

Event counter (N393)

1 to 10

4

Network side polling timer (T392)

5 to 30

(in seconds)

15

(in seconds)