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Occasional Contributor
Posts: 9
Registered: ‎04-27-2013

VC calculation and Shared Area Mode

Hello,


We'd like to make sure, when attaching a new array to x6-directors, that initiator traffic to the storage ports will spread evenly across Virtual Channels.
As far as I have learned, the DID of an FC frame determines which VC is being used. more specifically the lower 2 or 4? bits of the area id. Can someone please confirm this?
And in addition: what about the shared area mode used with the 48-port blades - these use 2 bits from the node-address-byte of the FCID. Are these 2 bits relevant for VC calculation?  
Thank you for your thoughts.

 

Regards

Joachim

External Moderator
Posts: 5,645
Registered: ‎02-23-2004

Re: VC calculation and Shared Area Mode

Occasional Contributor
Posts: 9
Registered: ‎04-27-2013

Re: VC calculation and Shared Area Mode

Thanks for the link – it answers first part of my question very well,

anyway about the 2nd part of my question regarding “shared area” (10bit area id) affecting VC, I am not sure yet.

Looking at FC-SW-6 standard regarding "virtual channels" it also mentions bit8 to 9 of D_ID for 4VCs and does not mention "shared area".

If someone has researched the topic already and came to a conclusion, I'd be glad to read from you.

 

TIA

Joachim

 

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Super Contributor
Posts: 320
Registered: ‎04-04-2018

Re: VC calculation and Shared Area Mode

Hello,

Yes, 8 an 9 bite is last two bites of D_ID.

Shared area will affect only number of NPIV devices attached to particular port as it will borrow bits from Node_ID.

Please mark this response as "Accept as Solution" if it answers your question.

Marian Bezeg

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