Some controllers do not follow the recommendation of auto-initiating
a data length update if the host writes default data length parameters.
If the controller follows this recommendation, calling
LE Write Suggested Default Data Length command is sufficient
to ensure that the LL will auto-initiate the DLE procedure. Performing
a second procedure is unecessary.
In Core v5.2, Vol 4, Part E, Section 7.8.35:
The HCI_LE_Write_Suggested_Default_Data_Length command allows the
Host to specify its suggested values for the Controller's maximum
transmission number of payload octets and maximum packet
transmission time for packets containing LL Data PDUs to be used
for new connections. The Controller may use smaller or larger values
for connInitialMaxTxOctets and connInitialMaxTxTime based on local
information.
In short, this command sets connInitialMaxTxOctets
and connInitialMaxTxTime.
In Core v5.2, Vol 6, Part B, Section 4.5.10:
For a new connection: connMaxTxOctets shall be set to
connInitialMaxTxOctets and connMaxRxOctets shall be chosen by the
Controller. If either value is not 27 then the Controller should
initiate the Data Length Update Procedure at the earliest practical
opportunity.
Signed-off-by: Rubin Gerritsen <rubin.gerritsen@nordicsemi.no>
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