S/UNI®-ATLAS-3200 Telecom Standard Product Data Sheet
Preliminary
PCR max = 5651328 cells/s
(this is the maximum cell rate at 2488 Mbps)
1
T min =
= 176.949 ns
PCR max
TAT min (0.125)(8ns)
Accuracy =
=
= 0.00565 = 0.57%
176.949 ns
Thus, the accuracy of the S/UNI-ATLAS-3200 policing algorithm satisfies the ITU-T I.371
recommendation of 1%.
It is important to note that since the Limit field is a floating-point number, its maximum value
exceeds the maximum TAT (2147483647) value; therefore, L should not exceed this value. If the
encoded value of L is greater than TATmax, then L shall be taken to be TATmax. Thus,
L ≤ TATmax
The value of ∆t and the range of I and L determine the lowest PCR that can be policed, the PCR
granularity supported at the highest expected PCR and the largest CDV expected.
1
PCRmin
=
Imax
granularity as a fraction of PCR = PCR
τmax = Lmax ∆t
(
∆t
)
(∆t
)
(
)
The maximum value for increment field supported in the S/UNI-ATLAS-3200 is
228 –1 = 268435455, therefore, the smallest peak (or sustainable) cell rate supported is PCRmin
0.465 cells/s
=
As described previously, the Limit field, L is a 14-bit floating point field, with Lmax = TATmax
2147483647. Therefore, with an 8ns cycle time, CDVmax = 17.18 s.
=
Note, the PCR (or SCR) and CDV (or BT) can be changed while the connection is provisioned
without disrupting the policing algorithm. That is, the Increment and Limit fields may be
changed at any point, and the policing algorithm will immediately begin policing to the new
settings.
The action taken on a non-conforming cell is programmed on a per-connection basis by the
Action1[1:0] and Action2[1:0] fields in Row 0 of the VC Table (Action1 controls the action taken
when a cell is non-conforming with GCRA1, and Action2 controls the action taken when a cell is
non-conforming with GCRA2).
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990553, Issue 4
95
PMC [ PMC-SIERRA, INC ]
