Cisco Systems 8600 Series manual Pcr, Cdvt, Vsvd, Scr, Mbs, Efci

ATM Connection Configuration

Table 7-4	Connection Parameter Descriptions
Parameter		Description
PCR		Peak cell rate:
		The cell rate which the source may never exceed
%Util		% Utilization; bandwidth allocation for: VBR, CBR, UBR it’s PCR*%Util, for ABR
		it’s MCR*%Util
MCR		Minimum Cell Rate:
		A minimum cell rate committed for delivery by network
CDVT		Cell Delay Variation Tolerance:
		Controls time scale over which the PCR is policed
FBTC (AAL5 Frame Basic Traffic		To enable the possibility of discarding the whole frame, not just one non-compliant
Control)		cell. This is used to set the Early Packet Discard bit at every node along a connection.
VSVD		Virtual Source Virtual Destination:
		(see Meaning of VSVD and Flow Control External Segments, Figure 7-7)
FCES (Flow Control External		(see Meaning of VSVD and Flow Control External Segments, Figure 7-7)
Segments)
SCR		Sustainable Cell Rate:
		Long term limit on the rate a connection can sustain
MBS		Maximum Burst Size:
		Maximum number of cells which may burst at the PCR but still be compliant. Used to
		determine the Burst Tolerance (BT) which controls the time scale over which the SCR
		is policed
Policing		(see definitions of Traffic Policing, Table 7-2)
VC QDepth		VC Queue Depth
CLP Hi		Cell Loss Priority Hi threshold (% of VC QMax)
CLP Lo/EPD		Cell Loss Priority Low threshold (% of VC QMax)/Early Packet Discard. If AAL5
		FBTC = yes, then for the BXM card this is the EPD threshold setting. For ASI cards,
		regardless of the FBTC setting, this is the CLP Lo setting.
EFCI		Explicit Forward Congestion Indication threshold (% of VC QMax)
ICR		Initial Cell Rate:
		The rate at which a source should send initially and after an idle period
ADTF (ATM Forum TM 4.0 term)		The Allowed-Cell-Rate Decrease Factor:
		Time permitted between sending RM-cells before the rate is decreased to ICR

Trm (ATM Forum TM 4.0 term)

An upper bound on the time between forward RM-cells for an active source, i.e., RM cell must be sent at least every Trm msec

RIF (ATM Forum TM 4.0 term)	Rate Increase Factor:
	Controls the amount by which the cell transmission rate may increase upon receipt of
	an RM cell
RDF (ATM Forum TM 4.0 term)	Rate Decrease Factor:
	Controls the amount by which the cell transmission rate may decrease upon receipt of
	an RM cell

ATM Connections 7-11