TSAT 3000 - Lcc_Management_Priority; Lcc_{Min | Max}_Retrans_Delay; Lcc_{Min | Max}_Reset_Retrans_Delay

TSAT 3000 - Telemetry and data transfer via SATellite
TSAT 3000 Configuration Parameter Description, January 2013 Page 60 of 124
3.8.6 LCC_MANAGEMENT_PRIORITY
Default 7, Range 0…7
Set the default priority of packets containing Management-Data. Some Management packets may
use other priorities.
Note: For the moment, all Management-Data packets are assigned hardcoded priority 7.
Ver >= 30.1.0
The “Management Slot Reservation (MSR) Facility” is enabled when
LCC_MANAGEMENT_
PRIORITY
= 7. MSR will reserve inbound slots for Management-Data, and try to ensure that
RTs only send Management-Data in such reserved slots. By this way, less collision with User-
Data is achieved.
Note: This facility should
be disabled in networks containing CCU Ver 30.0.0. I.e. set LCC_
MANAGEMENT_PRIORITY
<= 6.
Description of how the MSR facility is working:
• Whenever the HUB is sending or receiving a Management-Data packet to/from an RT, it will
reserve 50% of the next Round-trip slots to this RT.
• When it’s less than 2 seconds since an RT sent a Management-Data packet to HUB, it will
only send Management-Data in such reserved slots. Otherwise, it will follow the normal slot
allocation scheme.
See also
LCC_TX_QUE_SIZE
PORT_TX_QUEUE_SIZE [n]
MAC_SLOT_MAP_{0 | 1 | 2 | 3}
MAC_SLOT_REQ_RSV
3.8.7 LCC_{MIN | MAX}_RETRANS_DELAY
Default {2000 | 3000}, Range 600…60000
Lost packets on the satellite link are retransmitted after a random delay in this range, provided
that “Secure Link Facility” is enabled (see
PORT_MAX_APPL_RETRIES [n]). The interval is
doubled after 3 retransmissions.
The values are given in milliseconds, and applicable for both NETWORK and APPLICATION layer
packets.
LINK layer packets (i.e. LINK_RESET) retransmission delays are controlled by LCC_{MIN |
MAX}_RESET_RETRANS_DELAY
(default 10 ... 20 seconds).
Note: INFO_ACK (“Secure Link” acknowledge) isn’t sent to remote node immediately, but delayed
to match
LCC_MIN_RETRANS_DELAY of the other side. CCU will obtain and use the peer
node’s value of
LCC_MIN_RETRANS_DELAY when Link is Opened (CCU exchange
LINK_RESET and LINK_ACK packets). It’s therefore advisable to also Re-Open the LINK after
CURRENT value has been changed.
3.8.8 LCC_{MIN | MAX}_RESET_RETRANS_DELAY
Default {10 | 20}, Range 5…255
Lost LINK_RESET packets on the satellite link are retransmitted after a random delay in this
range. The interval is doubled after 3 retransmissions. The values are given in seconds
.