Update some help comments in two Kconfig files.

This commit is contained in:
Gregory Nutt 2018-07-04 15:36:31 -06:00
parent 22cd0d47fa
commit e1f8b3ff3b
2 changed files with 15 additions and 2 deletions

View File

@ -57,6 +57,9 @@ config NET_ETH_PKTSIZE
IPv6 hosts are required to be able to handle an MSS of 1220 octets,
resulting in a minimum buffer size of of 1220+20+40+14 = 1294
To get an MTU of 1500, for example, you would need packet buffer of
size 1514.
config NET_SLIP_PKTSIZE
int # "SLIP packet buffer size"
default 296
@ -67,7 +70,8 @@ config NET_SLIP_PKTSIZE
the TCP/UDP payload plus the size of TCP/UDP header and the IP header.
This value is related to the MTU (Maximum Transmission Unit), except
that it includes the size of the link layer header; the payload is
the MSS (Maximum Segment Size).
the MSS (Maximum Segment Size). SLIP has no link layer header so for
SLIP the MTU is the same as the PKTSIZE.
SLIP is required to support at least 256+20+20 = 296. Values other than
296 are not recommended.
@ -185,6 +189,13 @@ config NET_TUN_PKTSIZE
int "TUN packet buffer size"
default 296
range 296 1518
---help---
Provides the size of the TUN packet buffers. This size includes
the TCP/UDP payload plus the size of TCP/UDP header and the IP header.
This value is related to the MTU (Maximum Transmission Unit), except
that it includes the size of the link layer header; the payload is
the MSS (Maximum Segment Size). TUN has no link layer header so for
TUN the MTU is the same as the PKTSIZE.
choice
prompt "Work queue"

View File

@ -296,7 +296,9 @@ config NET_6LOWPAN_PKTSIZE
size of TCP/UDP header, the IP header, and the Ethernet header.
This value is related to the MTU (Maximum Transmission Unit), except
that it includes the size of the link layer header; the payload is
the MSS (Maximum Segment Size).
the MSS (Maximum Segment Size). 6LoWPAN has no link layer header (at
least in the packet buffer which is only used for re-assembly). So
for 6LoWPAN the MTU is the same as the PKTSIZE.
NOTE that this option depends on fragmentation support. By
supporting fragmentation, we can handle quite large "logical" packet