PM7312 pmc-sierra, PM7312 Datasheet - Page 19

• Manufacturer Part Number: PM7312
• Description: Freedm 32a1024l Assp Telecom Standard Datasheet
• Manufacturer: pmc-sierra

Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2021833, Issue 2
2.3
PPP Features
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o Capable of supporting fragment sizes from 6 to 9.6K bytes with the restriction that the
o Support for 3 egress fragmentation sizes (128, 256, and 512 bytes) configurable per
o Either 12 bit or 24 bit sequence number, with short and long fragment header formats, is
o Supports 16 bundles in ingress direction. These bundles are composed of independent
o Supports 16 bundles in egress direction. These bundles are composed of independent
o Support for fragmentation on a single HDLC channel.
o Support for 16 COS levels in accordance with RFC 2686.
o Support for up to 100ms of intra bundle skew in the receive direction when supporting the
o Up to 12 member links per bundle.
For each HDLC channel, the receiver checks for packet abort sequences, octet alignment,
and for minimum and maximum packet length.
For each HDLC channel, time-slots are selectable to be in 56 Kbps format or 64 Kbps clear
channel format.
For each HDLC channel, the HDLC transmitter supports programmable flag sequence
generation, bit stuffing and frame check sequence generation. The transmitter supports the
generation of both CRC-CCITT and CRC-32 frame check sequences. The transmitter also
aborts packets under the direction of the external TM engine or automatically when the
channel underflows.
Support for 2 levels of transmit priority per HDLC channel. (Only single link channels
support this feature, not multi-link bundles.) High and low priority packets are queued
separately. High priority traffic, when present, is always transmitted before low priority
traffic. When low priority traffic is fragmented, high priority traffic is inserted in between
low priority fragments.
Link Control Protocol packet identification. Packets are identified by the PID as control
protocols and will be forwarded to the Any-PHY interface.
Capable of supporting line rate transfers of packet sizes from 40 to 9.6K bytes.
Support for PPP header compression as per RFC 1661 on sequenced links. On receive,
compressed headers are detected and processed appropriately as they arrive on an HDLC
channel. Compressed PPP headers are passed to the system side via the Any-PHY interface.
On transmit, compressed headers are accepted from the system side device via the Any-PHY
interface. On sequenced links, all required processing is provided to correctly insert the
compressed PPP headers into the 1024 HDLC channels. On non-sequenced links, header
compression is only supported through the use of transparent mode.
RFC-1990 Multi-link PPP bundles:
maximum number of fragments per packet is 81.
connection. Optionally, full packet transfers are supported on a per connection basis. The
FREEDM 32A1024L supports header compression but does not perform it.
supported.
HDLC channels.
HDLC channels.
minimum fragment size. Capable of supporting larger skews (<400ms) with larger fragment
sizes. The intra-bundle skew is limited by 12 bit sequence number capabilities.
FREEDM 32A1024L ASSP Telecom Standard Product Data Sheet
Released
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