Cisco Systems MGX 8220 FRSM Service Interworking Connections, FUNI and Frame Forwarding

5-5
Cisco MGX 8220 Installation and Configuration
Release 5.0, Part Number 78-6430-03 Rev. D0, November 2003
Chapter Setting up a Frame Relay Connection
Minimum Cell Rate (MCR) is only used with ForeSight (ATFST).
MCR and Peak Cell Rated (PCR) should be specified according to the following formula:
MCR = CIR * 3/800 ce lls per second
PCR = AR * 3/800 cel ls p er s e cond but less than or e qu a l to 6 000
AR = Frame Relay port speed in bp s.
The above MCR and PCR formulae assume a fairl y pessimistic frame si ze of 100 octets, however even
smaller frame sizes can result in worst-case scenarios. For example,
The % Util should normally b e set to the same value as that used f o r t he F ra me R elay segments of the
connection.
FRSM Service Interworking Connections
FRSM service interworking connections are made in the same manner as the network interworking
connections except that chan_typ e i n th e M G X 8 2 20 addchan co mm a nd i s s p eci fied a s ser vice
interworking (transparent or translation) and the connection end that is remote from the MGX 8220 is
an ATM UNI.
FUNI and Frame Forwarding
These services are setup the sa me a s Frame Relay except the for por t_ ty pe in t he addchan comma nd,
which is set as 2 for FUNI or 3 for frame forwarding.
Table5-1 addcon Parameters
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