This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
Optimal 6loWPAN Configuration
-----------------------------
1. Link local IP addresses:
128 112 96 80 64 48 32 16
fe80 0000 0000 0000 xxxx xxxx xxxx xxxx
2. MAC-based IP addresses:
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
Where MMM is the 2-byte rime address XOR 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
3. MAC based link-local addresses
128 112 96 80 64 48 32 16
---- ---- ---- ---- ---- ---- ---- ----
fe80 0000 0000 0000 0000 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
4. Compressable port numbers in the rangs 0xf0b0-0xf0bf
5. IOBs: Must be big enough to hold one IEEE802.15.4 frame (CONFIG_NET_6LOWPAN_FRAMELEN,
typically 127). There must be enough IOBs to decompose the largest IPv6
packet (CONFIG_NET_6LOWPAN_MTU, default 1294, plus per frame overhead).
Fragmentation Headers
---------------------
A fragment header is placed at the beginning of the outgoing packet just
after the FCF 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
fragments of the same payload.
3. Datagram offset identifies the fragment’s offset within the un-
fragmented payload (in units of 8 bytes).
The length of the fragment header length is four bytes for the first header
(FRAG1) and five bytes for all subsequent headers (FRAGN). For example,
this is a HC1 compressed first frame of a packet
01 08 01 0000 3412 ### 7-byte FCF header
c50e 000b ### 4-byte FRAG1 header
42 ### SIXLOWPAN_DISPATCH_HC1
fb ### RIME_HC1_HC_UDP_HC1_ENCODING
e0 ### RIME_HC1_HC_UDP_UDP_ENCODING
00 ### RIME_HC1_HC_UDP_TTL
10 ### RIME_HC1_HC_UDP_PORTS
0000 ### RIME_HC1_HC_UDP_CHKSUM
80 byte Payload follows:
4f4e452064617920 48656e6e792d7065 6e6e792077617320 7069636b696e6720
757020636f726e20 696e207468652063 6f726e7961726420 7768656e2d2d7768
61636b212d2d736f 6d657468696e6720 g
This is the second frame of the same transfer:
01 08 01 0000 3412 ### 7-byte FCF header
e50e 000b 0a ### 5 byte FRAGN header
42 ### SIXLOWPAN_DISPATCH_HC1
fb ### RIME_HC1_HC_UDP_HC1_ENCODING
e0 ### RIME_HC1_HC_UDP_UDP_ENCODING
00 ### RIME_HC1_HC_UDP_TTL
10 ### RIME_HC1_HC_UDP_PORTS
0000 ### RIME_HC1_HC_UDP_CHKSUM
80 byte Payload follows:
6869742068657220 75706f6e20746865 20686561642e2027 476f6f646e657373
2067726163696f75 73206d6521272073 6169642048656e6e 792d70656e6e793b
202774686520736b 79277320612d676f
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.
