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Update a README

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Gregory Nutt
2017-04-24 09:42:51 -06:00
parent 745d862f53
commit 3c1d85af32
1 changed files with 12 additions and 10 deletions
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net/sixlowpan/README.txt
+12 -10
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@@ -10,12 +10,14 @@ Optimal 6loWPAN Configuration
128 112 96 80 64 48 32 16
---- ---- ---- ---- ---- ---- ---- ----
xxxx xxxx xxxx xxxx xxxx 00ff fe00 MMMM 2-byte Rime address IEEE 48-bit MAC
fe80 0000 0000 0000 NNNN NNNN NNNN NNNN 8-byte Rime address IEEE EUI-64
AAAA xxxx xxxx xxxx xxxx 00ff fe00 MMMM 2-byte Rime address IEEE 48-bit MAC
AAAA 0000 0000 0000 NNNN NNNN NNNN NNNN 8-byte Rime address IEEE EUI-64
Where MMM is the 2-byte rime address XOR 0x0200. For example, the MAC
Where MMM is the 2-byte rime address XORed 0x0200. For example, the MAC
address of 0xabcd would be 0xa9cd. And NNNN NNNN NNNN NNNN is the 8-byte
rime address address XOR 02000 0000 0000 0000
rime address address XOR 02000 0000 0000 0000.
For link-local address, AAAA is 0xfe80
3. MAC based link-local addresses
@@ -33,9 +35,9 @@ Optimal 6loWPAN Configuration
Fragmentation Headers
---------------------
A fragment header is placed at the beginning of the outgoing packet just
after the MAC when the payload is too large to fit in a single IEEE 802.15.4
frame. The fragment header contains three fields: Datagram size, datagram tag
and datagram offset.
after the MAC header when the payload is too large to fit in a single IEEE
802.15.4 frame. The fragment header contains three fields: Datagram size,
datagram tag and datagram offset.
1. Datagram size describes the total (un-fragmented) payload.
2. Datagram tag identifies the set of fragments and is used to match
@@ -65,7 +67,7 @@ this is a HC1 compressed first frame of a packet
This is the second frame of the same transfer:
41 88 01 cefa 3412 cdab ### 9-byte MAC header
e50e 000b 0a ### 5 byte FRAGN header
e50e 000b 0d ### 5 byte FRAGN header
42 ### SIXLOWPAN_DISPATCH_HC1
fb ### RIME_HC1_HC_UDP_HC1_ENCODING
e0 ### RIME_HC1_HC_UDP_UDP_ENCODING
@@ -81,5 +83,5 @@ This is the second frame of the same transfer:
The payload length is encoded in the LS 11-bits of the first 16-bit value:
In this example the payload size is 0x050e or 1,294. The tag is 0x000b. In
the second frame, the fifth byte contains the offset 0x0a which is 10 << 3 =
80 bytes, the size of the payload on the first packet.
the second frame, the fifth byte contains the offset 0x0d which is 13 << 3 =
104 bytes, the size of the payload on the first packet.