User's Manual

Table Of Contents
U
M10936
P
N7150 User Manual
UM
10936 All information provided in this document is subject to legal disclaimers.
U
ser manual
CO
MPANY PUBLIC
Rev. 2.06 November 2020
348120
18 of 127
2.
3.4 Segmentation and Reassembly
T
he Segmentation and Reassembly functionality SHALL be supported by both the DH and
the NFCC.
Segmentation and Reassembly of Messages SHALL be performed independently for
Control Packets and Data Packets of each Logical Connection.
Any NCI Transport Mapping is allowed to define a fixed Maximum Transmission Unit (MTU)
size in octets. If such a Mapping is defined and used, then if either DH or NFCC needs to
transmit a Message (either Control or Data Message) that would generate a Packet
(including Packet Header) larger than the MTU, the Segmentation and Reassembly (SAR)
feature SHALL be used on the Message.
The following rules apply to segmenting Control Messages:
For each segment of a Control Message, the header of the Control Packet SHALL
contain the same MT, GID and OID values.
From DH to NFCC: the Segmentation and Reassembly feature SHALL be used when
sending a Command Message from the DH to the NFCC that would generate a Control
Packet with a payload larger than the “Max Control Packet Payload Size” reported by
the NFCC at initialization. Each segment of a Command Message except for the last
SHALL contain a payload with the length of “Max Control Packet Payload Size”.
From NFCC to DH: when an NFCC sends a Control Message to the DH, regardless
of the length, it MAY segment the Control Message into smaller Control Packets if
needed for internal optimization purposes.
The following rules apply to segmenting Data Messages:
For each segment of a Data Message, the header of the Data Packet SHALL contain
the same MT and Conn ID.
From DH to NFCC: if a Data Message payload size exceeds the Max Data Packet
Payload Size, of the connection then the Segmentation and Reassembly feature
SHALL be used on the Data Message.
From NFCC to DH: when an NFCC sends a Data Message to the DH, regardless of
the payload length it MAY segment the Data Message into smaller Data Packets for
any internal reason, for example for transmission buffer optimization.