Multiplexing Multiple Ethernets on Fiber

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Archived from groups: comp.dcom.lans.ethernet (More info?)

I want to multiplex four or eight Ethernet channels over 1400' of
62.5/125 MMF. Can someone tell me who makes this type of equipment,
what it's called, and what's the least I should expect to pay for both
sides?

--
Bob Simon
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[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

Bob Simon <bsimon@xtne.net> wrote:
> I want to multiplex four or eight Ethernet channels over 1400' of
> 62.5/125 MMF. Can someone tell me who makes this type of equipment,
> what it's called, and what's the least I should expect to pay for both
> sides?

You could use VLAN in a pair of bridges ...

--
Peter Håkanson
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[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

phn@icke-reklam.ipsec.nu wrote:
> Bob Simon <bsimon@xtne.net> wrote:
>
>>I want to multiplex four or eight Ethernet channels over 1400' of
>>62.5/125 MMF. Can someone tell me who makes this type of equipment,
>>what it's called, and what's the least I should expect to pay for both
>>sides?
>
>
> You could use VLAN in a pair of bridges ...
>


I think he was thinking more along the lines of wave division
multiplexing. Ya know, running several gig ethernet connections over 1
single fiber.

Vlans are not a replacement for that since you are stuck with 1 gig to
multiplex them all over.

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

On Wed, 01 Sep 2004 16:18:08 -0400, "T. Sean Weintz"
<strap@hanh-ct.org> wrote:

>phn@icke-reklam.ipsec.nu wrote:
>> Bob Simon <bsimon@xtne.net> wrote:
>>
>>>I want to multiplex four or eight Ethernet channels over 1400' of
>>>62.5/125 MMF. Can someone tell me who makes this type of equipment,
>>>what it's called, and what's the least I should expect to pay for both
>>>sides?
>>
>>
>> You could use VLAN in a pair of bridges ...
>
>I think he was thinking more along the lines of wave division
>multiplexing. Ya know, running several gig ethernet connections over 1
>single fiber.
>
>Vlans are not a replacement for that since you are stuck with 1 gig to
>multiplex them all over.

Yes, after reading a couple of articles I see that WDM is what I want
to do. Do you need separate hardware for this or can you plug a GBIG
in a switch or a network module in a router router to get this
capability? (I have a 2924 and 3640.)

--
Bob Simon
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[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

Bob Simon wrote:

> On Wed, 01 Sep 2004 16:18:08 -0400, "T. Sean Weintz"
> <strap@hanh-ct.org> wrote:

>>phn@icke-reklam.ipsec.nu wrote:
>>> Bob Simon <bsimon@xtne.net> wrote:
>>>
>>>>I want to multiplex four or eight Ethernet channels over
>>>> 1400' of
>>>>62.5/125 MMF. Can someone tell me who makes this type of
>>>> equipment,
>>>>what it's called, and what's the least I should expect to
>>>> pay for both
>>>>sides?
>>>
>>>
>>> You could use VLAN in a pair of bridges ...
>>
>>I think he was thinking more along the lines of wave division
>>multiplexing. Ya know, running several gig ethernet connections
>> over 1
>>single fiber.
>>
>>Vlans are not a replacement for that since you are stuck with 1 gig
>> to
>>multiplex them all over.

> Yes, after reading a couple of articles I see that WDM is what I want
> to do. Do you need separate hardware for this or can you plug a GBIG
> in a switch or a network module in a router router to get this
> capability? (I have a 2924 and 3640.)

> --
> Bob Simon
> remove x from domain for private replies

You'd certainly need separate hardware on both ends for handling DWDM (or
WDM to that matter) that would have prisms to break the light down to
separate wavelengths and then combine it back. These are bulky and will
not fit into your regular GBIC footprint, at least for now. They will
definitely make them smaller in the future, but not yet as a commercial
product.

--
Dmitri Abaimov, RCDD
http://www.cabling-design.com
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premises cabling users and pros
http://www.cabling-design.com/homecabling
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[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

"Bob Simon" <bsimon@xtne.net> wrote:

>I want to multiplex four or eight Ethernet channels over 1400' of
> 62.5/125 MMF. Can someone tell me who makes this type of equipment,
> what it's called, and what's the least I should expect to pay for both
> sides?

If you buy a simple Ethernet multiport bridge, normally now referred to
as "layer 2 switch," the Ethernet frames from any of the ports will be
sent to any other port as required. Sometimes they are flooded to all
ports (e.g. in the case of Ethernet broadcasts such as ARP queries),
other times they are sent to the port that reaches the destination host.

So by definition, a switch should do what you ask.

However, if the Ethernets you are "multiplexing" each belong to a unique
IP subnet, then the box you need is not a layer 2 switch but rather a
router, also known as "layer 3 switch." One of the router ports can be
connected to the long link.

The 1400 ft length should be okay for multimode 62.5/125 um fiber even
with Gigabit Ethernet, but only at the 1300 nm wavelength. If you use
850 nm, you're limited to about 720 ft. At lower speeds, e.g. 10 or 100
Mb/s, no problem meeting that length requirement with short or long
wavelength.

If you expect to migrate to really fast stuff, like 10Gb/s Ethernet, use
of multimode fiber becomes more complicated. It is possible with some
combinations out to 300 meters (984 ft.). Probably safer to stick with
single-mode fiber in the long links, if you expect to go to 10G.

Bert

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

"Bob Simon" <bsimon@xtne.net> wrote:

> Yes, after reading a couple of articles I see that WDM is what I want
> to do. Do you need separate hardware for this or can you plug a GBIG
> in a switch or a network module in a router router to get this
> capability? (I have a 2924 and 3640.)

Why do you want to use WDM? I mean, if all you need is to send frames
from multiple segments down a single trunk segment, that's very
straightforward stuff.

Bert

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

On 2 Sep 2004 04:13:42 -0700, anybody43@hotmail.com (AnyBody43) wrote:

>Hi,
>
>You haven't said what total bandwidth you require. If it is < 1G bps
>in each direction then it is easy and cheap. You just use 1000BaseLX
>(GBICS, SMF) and VLAN trunking. You will need a mode conditioning
>cable for each end too.

Several folks have recommended VLANs. I would really prefer greater
isolation between streams but VLANs may work for me until I run out of
bandwidth. With gigabit, I hope we'll be able to defer CWDM for at
least a year. Although I don't have SMF, Albert mentioned that I'll
be able to run gigabit 1400' over MMF at 1300 nm.

Are VLANs protocol independent? What is a mode conditioning cable?

>Note that LX GBICS are single Mode and can be used with 62.5/125
>cable.

I'll research the various types and capabilities of GBICs this
afternoon.

>Maybe other single mode technologies (WDM) would work too? However I
>imagine that there would be no support available even if it did work.

Thanks but I would not be comfortable deploying a solution designed
for SMF over MMF. Network stability is critical.

--
Bob Simon
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[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

On Wed, 1 Sep 2004 21:58:51 GMT, "Albert Manfredi"
<albert.e.manfredi@nospam.com> wrote:

>The 1400 ft length should be okay for multimode 62.5/125 um fiber even
>with Gigabit Ethernet, but only at the 1300 nm wavelength. If you use
>850 nm, you're limited to about 720 ft. At lower speeds, e.g. 10 or 100
>Mb/s, no problem meeting that length requirement with short or long
>wavelength.

Bert,
Thanks for putting me on the right track. Your suggestion to use a
gigabit link and VLANs will save a lot of $$.

I also found an interesting article on the mode-conditioning patch
cord which explains everything I need to know about it.
http://www.cisco.com/en/US/products/hw/switches/ps679/products_installation_and_configuration_guide09186a008007d1cb.html



--
Bob Simon
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[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

On 2 Sep 2004 04:13:42 -0700, anybody43@hotmail.com (AnyBody43) wrote:

[snip]
>If you need more bandwidth than 1Gbps then you are into WDM
>territory
[snip]

1Gbps is hardly the highest rate available per wavelength. 10G
Ethernet equipment has been available for a few years. It's still
rather too expensive for most applications though.

There are also technologies other than Ethernet that could be used for
trunking, e.g. POS at 10G or 40G. These are also expensive.

Regards,
Allan

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

"Allan Herriman" wrote:

> 1Gbps is hardly the highest rate available per wavelength. 10G
> Ethernet equipment has been available for a few years. It's still
> rather too expensive for most applications though.
>
> There are also technologies other than Ethernet that could be used for
> trunking, e.g. POS at 10G or 40G. These are also expensive.

Exactly.

And the point is too that packet switched systems can naturally perform
"statistical multiplexing." In networks that have to support primarily
bursty data traffic, it would be very rare that all of the Ethernets
sharing that one trunk cable would experience peaks at exactly the same
time. This even holds true if the Ethernets are supporting compressed
video or audio streams.

So I wouldn't automatically assume that the trunk segment *must* have a
bandwidth equal to the simple sum of all Ethernet segments feeding it.
In most cases, that would be a very wasteful design.

Bert

 

[Stephen]

Archived from groups: comp.dcom.lans.ethernet (More info?)

"Allan Herriman" <allan.herriman.hates.spam@ctam.com.au.invalid> wrote in
message news:qm3ej09mfdn4k52fqnh6dutvk2iikl52mu@4ax.com...
> On 2 Sep 2004 04:13:42 -0700, anybody43@hotmail.com (AnyBody43) wrote:
>
> [snip]
> >If you need more bandwidth than 1Gbps then you are into WDM
> >territory
> [snip]
>
> 1Gbps is hardly the highest rate available per wavelength. 10G
> Ethernet equipment has been available for a few years. It's still
> rather too expensive for most applications though.

it also is going to struggle with the fibre spec - 400 meters of MMF is not
going to work with 10G unless you have exotic fibre.
>
> There are also technologies other than Ethernet that could be used for
> trunking, e.g. POS at 10G or 40G. These are also expensive.
>
> Regards,
> Allan
--
Regards

Stephen Hope - return address needs fewer xxs