m27651 Mindspeed Technologies, m27651 Datasheet - Page 2

• Manufacturer Part Number: m27651
• Description: Mindcontroller? Oc-12 Atm Shaper
• Manufacturer: Mindspeed Technologies

MindContoller™ OC-12 ATM Shaper
Congestion Management
Cells beginning the traffic shaping process are stored in
p e r-VC queues. The queues are constructed using buffe r s
from up to 16 buffer class e s. The size of each buffer class
is configurable at initialization,with a maximum buffer memory
s i ze for all classes of 512 Mbyte s. Cells are mapped to a
b u ffer class on a per-connection basis, with each class
typically representing an ATM quality of s e rvice (QoS)
( e. g . , C B R , r t V B R , nrtVBR or UBR).
Two configurable per-buffer class thresholds (CLP1 and
CLP01) and a per-connection threshold (CLP01) are provided.
Cell discard occurs (based on the CLP bit) when any of these
thresholds are exceeded, or when the buffer limit is reached.
EPD is optionally applied on AAL5 connections when a CLP01
Memory Configuration
threshold is exceeded. PPD is optionally applied on AAL5
connections when the buffer limit is reached.
Header Translation
The M27651 supports the standard 53-byte UNI and NNI cell
formats. For channel-switched connections (VCs and VP
endpoints), the VPI and VCI fields in the ATM cell header are
replaced with new values. For path-switched connections (VP
midpoints), only the VPI is replaced.The PTI and CLP fields
from input cells are copied and modified as appropriate.
Statistics
The M27651 provides the following statistics: aggregate cell
c o u n t , total discards, AAL5 packe ts and OAM cells. All counte r s
are available on a per-PHY and per-channel basis.