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draft-marushin-sctp-asconfext-01.txt
An extension to ADD-IP draft to send cumulativeASCONF chunks
draft-marushin-sctp-asconfext-01.txt
Shin Maruyama (Kyoto Univ., JAPAN)
Masahiro Kozuka (Kyoto Univ., JAPAN)
draft-marushin-sctp-asconfext-01.txt
Limitation on ASCONF transmission
• Sending new ASCONF chunk is prohibitedif outstanding ASCONF chunk exists.
• No modification on queued ASCONFs
draft-marushin-sctp-asconfext-01.txt
A typical scenario to break an association
• “Node A” supports IPv4 and IPv6 address• “Node B” supports only IPv4• “Node A” first loses IPv4 address and then get
another IPv4 address.Node A Node B
ASCONFDEL-IP(IPv4)
ASCONFADD-IP(IPv4)
Node A loses IPv4 address
Node A only has IPv6 address,ASCONF cannot be sent out
Once this happens, followingASCONFs are also blocked
IPv4
IPv6
IPv41.
2.
3.
draft-marushin-sctp-asconfext-01.txt
Another Typical Scenario• Node has a single interface and an IP
address, and the interface goes down.
• The node get another address, but the address is disconnected.
ASCONF
ASCONFADD-IP(IP3)
1.
2.
3.
IP1
ASCONF-ACK
IP1IP2
Node loses IP1
Get unreachable address IP2, ASCONF-ACK never returned
Get another reachable address IP3, but ASCONF cannot be sent out
draft-marushin-sctp-asconfext-01.txt
Cumulative ASCONF chunks
• On sending ASCONF chunks, if there are any outstanding ASCONFs, bind them up!
draft-marushin-sctp-asconfext-01.txt
Some Remarks• On bundling ASCONFs, all the outstanding ASCO
NFs must be bundled in order.
• ASCONF_ACK must be returned to the source address of bundled ASCONFs
• Receiver must return ASCONF_ACKs for all ASCONFS bundled even when some of themhave already processed.– ASCONF_ACK should be cached until the sender is ass
umed to have received it.
• ASCONF_ACK should also be bundled.
draft-marushin-sctp-asconfext-01.txt
Questions?
draft-marushin-sctp-asconfext-01.txt
BA
ASCONF 1,2
ASCONF 1,2,3,4,5
ACK 1,2
ASCONF 3,4,5
1,2
3,4,5
Retransmition
Ignored
Cache 1,2
Cache 3,4,5
ACK 3,4,5
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