... | ... | @@ -149,15 +149,18 @@ Improvements to AVB Gen 1: |
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### Requirements for AVB Gen 2
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- Network redundancy support - support of quick network recovery
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(\<100ms [Toyota,
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page 6](http://www.ieee802.org/1/files/public/docs2011/new-avb-KimNakamura-automotive-network-requirements-0311.pdf))
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and seamless redundancy with zero time recovery ([General
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Motors](http://www.ieee802.org/1/files/public/docs2012/new-avb-jochim-redundancy-requirements-GM-perspective-AVB2-0312.pdf)),
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this includes
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- communication recovery (RSTP)
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- \[re-\]synchronization (802.1AS)
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- \[re-\]reservation of stream (802.1Qat)
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- Network reliability:
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- support of quick network recovery (\<100ms [Toyota,
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page 6](http://www.ieee802.org/1/files/public/docs2011/new-avb-KimNakamura-automotive-network-requirements-0311.pdf))
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and seamless redundancy with zero time recovery ([General
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Motors](http://www.ieee802.org/1/files/public/docs2012/new-avb-jochim-redundancy-requirements-GM-perspective-AVB2-0312.pdf)),
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this includes
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- communication
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- synchronization (802.1AS)
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- reservation of stream (802.1Qat)
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- support of fault isolation/fault tolerance (e.g.: "babbling
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idiot" and "fault tolerant clock sync", [General Motors,
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pages 36](http://www.ieee802.org/1/files/public/docs2012/new-avb-jochim-redundancy-requirements-GM-perspective-AVB2-0312.pdf))
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- Ultra-low latency for critical traffic
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- Toyota
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([page 2](http://www.ieee802.org/1/files/public/docs2011/new-avb-nakamura-automotive-backbone-requirements-0907-v02.pdf))
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... | ... | @@ -216,13 +219,8 @@ The enhancements to current IEEE 802.1AS include |
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- aims at providing multiple paths for both redundancy and enhanced
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network throughput
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- b
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- c
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<!-- end list -->
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- Network redundancy support - actually two different types of
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redundancy are required
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- Network redundancy - actually two different types of redundancy are
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required
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- static redundancy - redundant paths from the source to the
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receiver exist and are used at any time - duplication of frames
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must be handled by the receiver (provides seamless redundancy)
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... | ... | @@ -242,3 +240,18 @@ The enhancements to current IEEE 802.1AS include |
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## **AVB *Gen2* vs. White Rabbit**
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- fault tolerance / isolation
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- we want to use VLANs to isolate different network and limit a
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propagation of destruction by mis-behaving node/switch
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- FEC header has ID and sequence number - can prevent some
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duplication issues
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- control of throughput from nodes which are not supposed to send
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too much data (if any)
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- isolation of different acceleration networks
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synchronization-wise (but not within accelerator network), as
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soon as we detect that connection with grandmaster is not valid
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(link down) we kill all the master ports not to propagate wrong
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time downstream (since we synchronize simultaneously to more
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then one source of time, it is possible to make
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voting/comparision)
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