Mainframe & FICON

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Occasional Contributor
Posts: 5
Registered: ‎02-28-2012

Clarification of DLS and IOD relevance with frame based trunks

Hello,

I'm looking to see if any is able to clarify whether a settings such as DLS and IOD are relevant options where a frame based trunk is established between 2 logical switches with dedicated ISLs in separate DCX chassis'?

I'm pretty sure IOD is not relevant as frame based infers that one frame traverses the ISLs as if they were one link hence preserving order by default.

DLS is one I am unsure of though - we intend to create a separate pair of logical switches on a pair of DCXs with dedicated ISLs (i.e. not using XISL) for the purpose of FICON traffic only.  As I understand it, DPS is not supported on FOS 6.4 so we are required to use frame based trunks for this fabric.

Thanks,

David

External Moderator
Posts: 4,857
Registered: ‎02-23-2004

Re: Clarification of DLS and IOD relevance with frame based trunks

David,

please post in the future such question in appropriate Mainframe Forum.

http://community.brocade.com/community/forums/products_and_solutions/mainframe_solutions

To you question:

--->>>As I understand it, DPS is not supported on FOS 6.4 so we are required to use frame based trunks for this fabric.

DPS = EBR = Exchange Based Routing is supported in FOS 6.4 as well, however is currently not supported for FICON, but can be utilized in a different logical switch on the same chassis when the VF = Virtual Fabric feature is enabled.

If you need more info, let me know.

TechHelp24
Occasional Contributor
Posts: 5
Registered: ‎02-28-2012

Re: Clarification of DLS and IOD relevance with frame based trunks

Sorry for that - should have spotted that this should live in the FICON forum.

Pretty much sure that this confirms for cascaded FICON on 6.4 our only supported ISL option is frame based trunking.

Thanks,

David

External Moderator
Posts: 4,857
Registered: ‎02-23-2004

Re: Clarification of DLS and IOD relevance with frame based trunks

David,

--->>> Pretty much sure that this confirms for cascaded FICON on 6.4 our only supported ISL option is frame based trunking.

I do not understand their comments, what they mean ?


TechHelp24
Eli
Contributor
Posts: 30
Registered: ‎03-14-2012

Re: Clarification of DLS and IOD relevance with frame based trunks

Hi,

Exchange Based Routing, IOD (In Order Delivery) are all supported in FOS 6.4.

However, for cascaded FICON the best practices are as follow:

1. Use Port Based Routing

2. IOD enabled

3. DLS (Dynamic Load Sharing) enabled with loseless feature.

NOTE: If Lossless DLS is not enabled, the routing policy must be port-based routing.

If you use single ISL (ot trunked), of course it don't have any meaning.

But consider the following: if you will add additional ISL's (or trunk), you will have to change this parameters to be compatible, and to change it- the switch must be disabled, so it will be disruptive operation.

My advice- configure all those parameters as described above, to avoid any problems in the future.

Regarding you thoughts- described parameters don't have any meaning in trunking (as you called "frame based trunking").

Moreover- you can't use XISL in FICON at FOS 6.4 !!! It not supported.

If you have any questions, let me know.

Brocadian
Posts: 103
Registered: ‎08-13-2009

Re: Clarification of DLS and IOD relevance with frame based trunks

Hello,

A point of clarification.  Exchange Based Routing (DPS) was originally supported by IBM for mainframe environments (FICON) with FOS 6.4.  That support was temporarily suspended due to channel microcode issues.

Steve

External Moderator
Posts: 4,857
Registered: ‎02-23-2004

Re: Clarification of DLS and IOD relevance with frame based trunks

Steve,

thanks that you have clarified about "not-supported" DPS in FICON environments.

Antonio

TechHelp24

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