FDDI Question

[OnyxINC]

Is there a faster mainframe network interface than FDDI, FDDI is token ring technology that works at 100Mbit...

 

[spidey07]

Not sure, but maybe there is a gigabit ethernet interface. really depends on the mainframe.

Have you tried calling support or your account rep? I'm assuming IBM here.

Are you thinking about switching?

<edit> what you eventually end up getting (or if you should change in the first place) depends heavily on the existing network. if your net is mostly token ring then there is no need to change, if it is mostly ethernet then you have justification. FDDI is still faster than fast ethernet is alot of aspects.

 

[L3Guy]

I am almost positive that there is an ATM OC-3 card for the mainframe. I've heard of an OC-12
caard, as well. However, I don't know if it ever actually shipped.
The fastest connection would likely be a channel-attached 7513 with a Gig blade.

FDDI is great, but equipment that actually supports it is becoming rare.


HTH

 

[spidey07]

good point L3,

the interface you choose should be based on your current or future network design. (what is the point of doing ATM if his whole network is frame based?)

channel attached 7513 will do whatever you want.

Is this for a front end processor and if so what model?

 

[OnyxINC]

We are moving away from Token Ring and therefore FDDI, I have called IBM to find out if AIX supports GB Ethernet interface cards but, we are having contract problems with them, and they won't help. I just need to find a site that has a list of GB Ethernet or at least 100Mbit ethernet which are compatible with AIX.... Thanks all!

 

[spidey07]

good deal, I went through that about two years ago.

FDDI attached FEP on a routed token ring network. FEP only had 10 Base-T as an ethernet option.

 

[Garion]

Saying &quot;a mainframe&quot; is kind of like saying &quot;a computer&quot;. Details, man, details!

You might have a tough time getting an answer to this one here, but it's worth a shot!

- G

 

[spidey07]

C'mon garion. You're the bank dude, you should be full of blue and SNA by now!!!

 

[Garion]

I can spell SNA, but that's about it. I'm an IP guy, hardcore! Plus, this isn't really a protocol question, it's a hardware question!

Now that I think about.. FDDI is pretty serious bandwidth for a mainframe - It can easily handle 100Mb/s. What kind of apps are you running on the mainframe that need more bandwidth than that?!?

- G

 

[L3Guy]

I personally would not replace FDDI with fast Ethernet.
FDDI is not &quot;token ring&quot; in any real sense, and FDDI
inter-operates well with Ethernet.

It seems to me that the reliable dual ring on fiber technology
is still very good for mainframe work.

Advantages:
Redundant Paths without spanning tree.
Fiber connections.
Ability to maintain 90+ % utilization.
Designed specifically for &quot;backbone&quot; use.

Disadvantages:
High per port cost.
Half duplex.
increasingly rare.
100 Mbps

Bottom Line: While I might not use it for new installations,
existing FDDI mainframe connections are still very good as long as
capacity isn't the only issue.

Just my opinion.

Doug

 

[spidey07]

The only real problem I've ran into with FDDI/FastEnet routing is the differences in frame sizes and the work a router has to perform to forward them. Get some IP fragmentation and additional overhead there.

This scenario really only showed itself during network based backups while moving 100s of gigabytes from fastE servers to a mainframe based backup system. Instead of taking 8 hours it took like 11, but when backup windows are small that is a huge difference.