Showing posts with label FC. Show all posts
Showing posts with label FC. Show all posts

Saturday, June 18, 2011

Well Known Addresses

          Every switch has reserved three byte addresses known as Well Known Addresses. The services residing at these addresses provide a service to either nodes or management applications in the fabric.
           Fabric Login : Before a fabric node can communicate with services on the switch or other nodes in the fabric an address is assigned by the fabric login server.
           Directory Server/Name server: The directory server/name server is where fabric/public nodes register themselves and query to discover other devices in the fabric.
            The fabric controller provides state change notifications to registered nodes when a change in the fabric topology occurs


Control Flow :

1. Fabric Login (Flogi) from host to switch at FFFFFE  (FABRIC LOGIN)

2. Switch(FFFFFE) responds with an ACCEPT

3. Host does an N-port login (Plogi) to the switch at FFFFFC

4. Switch FFFFFC Accepts

5. Host registers (SCR) to receive RSCN at FFFFFD

5. Host can then

       a) Register attributes

       b) Query for devices

6. Switch(FFFFFC) will respondas appropriate for type of request

7. Host may logout the Name Server (LOGO)- not the Fabric

SAN Attached Initiators and Target
        Initiator Communication Process Review
             Fabric Initiators are typically server HBAs that will:
             FLOGI to FFFFFE and obtain 24-bit Fabric address
             PLOGI to FFFFFC
                SCR to FFFFFD
                Register and query FFFFFC for database of Storage/Tape targets
  

                      FFFFFC matches HBA to zones (Fabric subsets containing devices you“allow” to communicate) and returns 24-bit addresses of targets that HBA requested within authorized  zones
 

                      PLOGI and then sends SCSI probes to fabric destination addresses of targets returned from Name Server
Assign target ids (with server OS) to each node

Brocade, Emulex kick off 16-gig FC hype

Ready or not, 16 Gbps Fibre Channel is coming.
Emulex and Brocade this week said they have 16-gig FC devices being qualified by storage and server vendors, although there doesn’t appear to be any screaming demand for organizations looking for more than 8-gig FC support. The aggressive move to 16-gig FC is a sign that mass adoption of Fibre Channel over Ethernet (FCoE) is still a long ways off and pure FC has plenty of life left.
Emulex got the ball rolling Monday with its XE201 I/O Controller, a converged adapter that supports 16-gig FC along with FCoE, 10-Gigabit Ethernet (GbE) and 40 GbE. Emulex will demo the XE201’s 16-gig capability at EMC World next week.
Brocade Tuesday rolled out what it calls the first end-to-end 16-gig FC platform of products. They include the DCX8510 Backbone SAN switch with up to 384 16-gig ports at line-rate speeds, the 6510 edge switch with 24 or 48 ports, and the 1860 Fabric Adapter that supports FC, Ethernet and FCoE. Brocade is also adding 16-gig FC support to its Network Advisor 11.1 unified management software and Brocade Fabric Manager 7.0.
Brocade said the new switches and software will be available this quarter. However, its OEM partners probably won’t complete qualifications before August. EMC and Hewlett-Packard are already qualifying the 16-gig products with other storage vendors to follow soon.
Emulex VP of marketing Shawn Walsh said he expects OEM certification for the second half of this year for Emulex’s 16-gig adapter.
It’s no surprise that Brocade is pushing the faster FC. Brocade has always been less bullish on FCoE than its FC switch rival Cisco, and Brocade picked up significant market share gains by beating Cisco to 4 Gbps and 8 Gbps FC gear. During its tech summit day Tuesday, Brocade execs said the market agrees with their take on FC and FCoE.
“FCoE adoption has been modest,” said Jason Nolet, VP of Brodcade’s data center and enterprise networking group.
“Our customers say they want to stay with Fibre channel,” Brocade CTO Dave Stevens added.
Emulex’s Walsh agreed with that. “Ten-gig [Ethernet] adoption is happening fast, but there’s still discrete networks,” he said. “Customers are not going to throw away what they have today. One of the big questions we get is, ‘What is Emulex’s commitment to 16-gig Fibre Channel?’”
It’s almost certain that more vendors will have 16-gig FC products by the Fibre Channel Industry Association (FCIA)’s October 16-gig plugfest.
If history is any indication, Cisco will trail Brocade by from six months to a year with 16 Gbps FC. Emulex’s main adapter rival QLogic isn’t commenting on its 16-gig roadmap but is expected to support it this year.
Brocade execs point to virtualization and the cloud as drivers of the faster technology. However, there will be a price premium to move from 8-gig to 16-gig. That was also the case with the move from 4-gig to 8-gig, and that transition was slower than the moves from 1-gig to 2-gig and from 2-gig to 4-gig when there was no price hike for the higher bandwidth. While the first two transitions took about two years each for the higher bandwidth to become dominant, the move to 8-gig took about three years.
In a blog post this week, Wikibon senior analyst Stuart Miniman advised organizations to pursue 16-gig FC and converged networks on their internal schedules rather than according to vendor roadmaps.
“Most users can take a slow and deliberate approach to the adoption of new generations of speeds,” Miniman wrote. “ … customers can support both FC and Ethernet and consider the migration on internal schedules rather than on the pace that the vendor community may want to push or pull. For equipment refresh cycles that start in 2012 or later, consider looking for adapters that can support the latest of both FC and Ethernet.”

Friday, June 17, 2011

FC Layers


Fibre Channel have Mainly five layers :

1. FC0 : Speeds and feeds. (Physical layer)
2. FC1 : 8b/10b encoding.
3. FC2 : Data delivery.
4. FC3 : Common services.
5. FC4 : Upper level protocals (Uper layers protocals mapping).


 FC0 :










  
Single mode Fibre and multi mode Fibre :

 FC0 Connector Distances :

FC0 Cable Connections :

FC Cable Components :

FC 1 :


FC 2 :


FC 2 Exchange Sequence Frame Management :


FC 2 frame format :

FC 2 CLASS OF SERVICE (COS) :


FC2 common class of service :


FC2 Flow Control :


FC 2 Buffer to Buffer Flow Control :


FC2 BB and end2end Flow control :


FC2 flow control cont..:

FC2 Control flow Summary :

FC 3  Layer COmmon services :

FC 4 Upper level protoval (ULP) Mapping :

FIBRE CHANNEL PROTOCAL MAPPINGS :



SUMMARY :)





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