Specifications
Service Configuration 5-5
Setting up a Frame Relay Connection
Establish the BPX to BPX Segment
The following steps should be performed to establish the required BPX to BPX segments.
1 Perform an addcon command at one of the BPX nodes (not both) as follows.
For slot number and port number, specify slot and port of the BNI port connected to MGX 8220.
For VPI, specify the slot number in the MGX 8220 shelf that contains the FRSM attached to the
BPX.
For VCI, specify the LCN (logical channel number) of the frame relay connection configured on
the local MGX 8220 shelf.
For Nodename, specify the nodename of the BPX at the other end of the connection.
For Remote Channel, specify the BNI slot and port number of the BNI port attached to
MGX 8220 at the remote end. Specify the VPI as the slot number of the remote MGX 8220
FRSM connected to the BPX and specify VCI as the LCN (logical channel number) of the frame
relay connection at the remote MGX 8220.
Specify the type of connection. ATFR when ForeSight is not being used and ATFST when
ForeSight is being used.
2 Specify the other addcon parameters of bandwidth, and so on.
Table5-1 Addcon Parameters
Minimum Cell Rate (MCR) is only used with ForeSight (ATFST).
MCR and Peak Cell Rated (PCR) should be specified according to the following formulae.
MCR = CIR *3/800 cells per second
PCR =AR * 3/800 cells per second but less than or equal to 6000
AR = Frame relay port speed in bps.
The above MCR and PCR formulae assume a fairly pessimistic frame size of 100 octects, however,
even smaller frame sizes can result in worse case scenarios. For example:
% Util should normally be set to the same value as that used for the frame relay segments of the
connection.
Parameter Description
MCR Minimum Cell Rate
PCR Peak Cell Rate
% Util Percentage utilization of channel
For example: AR equals 64K, PCR = 237, or
AR speed equals 256K, PCR = 950, or
AR speed equals 1536K, PCR = 5703
For a frame size of 64 octects the PCR formula becomes PCR = AR * 2/512 cells per sec
For a frame size of 43 octects the PCR formula becomes PCR = AR * 2/344 cells per sec