TSAT 3000 - 3.12.3 PKT_INBOUND_SIZE

TSAT 3000 - Telemetry and data transfer via SATellite
TSAT 3000 Configuration Parameter Description, January 2013 Page 98 of 124
3.12.3 PKT_INBOUND_SIZE
Read-Only
Read the number of bytes in a satellite Link packet from RT to HUB. It is calculated after the
restart of the Main Unit (and when any of DSP configuration parameters are changed), and is a
function of:
• PKT_OUTBOUND_SIZE
•
PHL_{OUTBOUND | INBOUND}_SYMBOLRATE
•
PHL_{OUTBOUND | INBOUND}_FECRATE
•
PHL_IN_OUT_PACKET_RATIO
•
PHL_INBOUND_GUARDPERIOD
•
PHL_SLOT_PHASE_MODE
PKT_INBOUND_SIZE should at least be greater or equal:
• Ver <= 30.1.1: 16 bytes, due to the size of
POLL_ACK, LINK_RESET and LINK_ACK packets.
• Ver == 30.2.0…30.3.1: 24 bytes, due to the size of
POLL_ACK packets.
Note: The Link will still work OK with
PKT_INBOUND_SIZE as low as 16 bytes, but some
information in the
POLL_ACK packet will be lost. That is GROUP information signalled
from RT to HUB. See
PORT_STREAM_RT [n].
• Ver >= 30.4.0: 26 bytes, due to the size of
POLL_ACK packets.
Note: The Link will still work OK with
PKT_INBOUND_SIZE less than 26 bytes (as older
versions do), but the HUB will not
be able to fetch the RT’s Satellite IP address from the
POLL_ACK packet. “IP Routed Line”, “IP Outbound Secure Link” and “IP Redundancy
Facility” will be disabled. See
PORT_STREAM_RT [n] and PORT_MAX_APPL_RETRIES [n].
• Ver >= 31.0.0: 27 bytes, due to the size of
POLL_ACK packets.
Note: The Link will still work OK with
PKT_INBOUND_SIZE less than 27 bytes (as older
versions do), but the HUB will not
be able to fetch the RT’s IP-Link-Options from the
POLL_ACK packet. This will affect the “Robust Header Compression (ROHC) Facility”
implemented in VxWorks 6.7 (Release 4.x.x).
A WARNING will be issued when it’s calculated to be less than minimum number of bytes.
3.12.4 PKT_POOL_SIZE
Default 300, Range 100…1000 – BOOT
Set the number of available packets in the CCU. It may cause loss of data if set too small.