3Com Router User Manual

Configure Frame Relay247
Note the following:
■The interfaces link layer protocol can be configured to Frame Relay only when 
it operates in the synchronous mode.
■When the interfaces link layer protocol is SLIP, the physical attributes of the 
interface cannot be modified to synchronous mode. At this time, you should 
first modify the link layer protocol of the interface to PPP and then you may 
change the interface attribute to synchronous mode.
The Frame Relay interface can send the packet in either of...

248CHAPTER 17: CONFIGURING FRAME RELAY
When the Frame Relay interface type is DCE or NNI, the default type of LMI 
protocol of interface is Q933a. When the Frame Relay interface type is DTE, the 
default LMI protocol of interface is null.
4Configure the Related Parameters of Frame Relay LMI Protocol
The procedure of the LMI protocol is as follow:
■DTE sends out a status enquiry message, and the timer T391 starts. T391 is set 
with the polling interval. In other words, DTE will send a status enquiry...

Configure Frame Relay249
The following table describes the value ranges and default values of related 
parameters of the Frame Relay LMI protocol
Ta b l e 278   Descriptions of related parameters of Frame Relay LMI protocol
In which, the related parameters at the DTE side include:
■T391DTE: The interval of the link integrity polling for the equipment at the DTE 
side
■N391DTE: DTE equipment will send a status enquiry message at a certain 
interval (which is determined by T391). The status enquiry...

250CHAPTER 17: CONFIGURING FRAME RELAY
N392, the DTE equipment will assume that the number of errors reaches the 
threshold, and will regard the physical path and all the virtual circuits as unusable.
The parameters at the DCE side include:
■T392DCE: Define the longest duration for the DCE equipment to wait for a 
status enquiry message. It should be larger than T391.
■N392DCE: The threshold for the errors that can occur in the total number of 
observed events at the DCE side.
■N393DCE: The total number...

Configure Frame Relay251
The map created through the dynamic inverse ARP has broadcast attribute.
6Configure Frame Relay Local Virtual Circuit Number
Perform the following configurations in synchronous serial interface view.
Ta b l e 281   Configure Frame Relay local virtual circuit number
After entering the DLCI view through the fr dlci command, the user can 
configure the parameters associated with this virtual circuit, such as Frame Relay 
class.
The virtual circuit number is valid locally, that is,...

252CHAPTER 17: CONFIGURING FRAME RELAY
bConfigure virtual circuit of Frame Relay sub-interface
In interface view, perform the following task to configure the virtual circuit of 
Frame Relay sub-interface.
Ta b l e 283   Configure virtual circuit of Frame Relay sub-interface
cConfigure Sub-Interface PVC and Establish Address Mapping
Since there is only one peer address for point-to-point sub-interface, the peer 
address is determined when a PVC is configured for the sub-interface. For 
point-to-multipoint...

Configure Frame Relay253
Perform “Enabling/Disabling Frame Relay PVC switching” in system view, and 
configure all the other commands in synchronous serial interface view.
Ta b l e 286   Configure the Frame Relay PVC switching
By default, Frame Relay PVC switching is disabled.
The configured PVC can take effect only when the type of Frame Relay 
interface is NNI or DCE.
bConfigure Frame Relay switched route
Perform the following configurations in synchronous serial interface view.
Ta b l e 287...

254CHAPTER 17: CONFIGURING FRAME RELAY
By default, no Frame Relay switched PVC is created.
After configuring the Frame Relay switched PVC, the user will enter the frame 
relay switch 
view to perform the operations of shutdown and undo shutdown 
on the switched PVC.
The differences between configuring a Frame Relay switched route and 
configuring a Frame Relay switched PVC are listed below:
1) A Frame Relay switched route can become valid only when it is configured on 
the two Frame Relay switched...

Configure Frame Relay255
will not take effect. On the MFR interface, you can configure the network layer 
parameters (e.g., IP address) and Frame Relay parameters (e.g., DLCI). The physical 
interface bundled on the MFR interface will use the parameters on the MFR 
interface. 
Configure MFR
The configuration tasks of the MFR are listed as follows:
■Configure a MFR Bundle
■Configure a MFR Bundle Link
1Configure a MFR bundle
Please perform the following configuration in system view.
Ta b l e 291...

256CHAPTER 17: CONFIGURING FRAME RELAY
Ta b l e 294   Configure the parameters of the bundle link interface
The default link identification is the name of its physical interface. 
By default, a bundle link will send out hello message every 10 seconds; it will send 
a hello message a maximum of 3 times and wait 4 seconds for a hello message 
acknowledgement.
Configure Frame Relay 
Payload Compression 
(FRF.9)Introduction to Frame Relay Payload Compression
Using the Frame Relay payload compression...