The Seattle SAGE Group
An Advanced Overview of IPv6
IPv6 Data types & flow control
- Data types determined by 4 bit Priority Field in header
- 0-7 are values that can respond to congestion
- 0 - Uncharacterized
- 1 - "filler" like netnews
- 2 - Unattended data transfer (email)
- 3 - reserved
- 4 - Attended bulk transfer (FTP, NFS, HTTP(?))
- 5 - reserved
- 6 - Interactive traffic (telnet, X)
- 7 - Internet control (RIP, SNMP)
- 8-15 are values that must be sent in "real time". In times of
congestion, a value of 8 will be discarded before a value of 9, etc, and
a value of 15 is data the sender wishes to always make it through if
possible.
- Flow Control
- More than 1 flow can be underway from a source to a dest
- Uses a flow label field in IPv6 header to fully specify a flow in
combination with the source/destination
- Is how routers will ID "real time" data.
- Routers may be able to optimize using flow labels
More info:
rfc1883