RE: Issues concerning 10GbE speed standards

[Drew Perkins <drew.perkins@xxxxxxxxxxxx>]

Peter and Roy,
	The cost of higher speed in the WAN is not so much that of the
electronic parts, but rather the fact that you need more of them for long
distances. This is because most optical effects such as dispersion increase
with the square of the distance. Thus increasing the speed by 25% increases
the optical effects by 56%, and that tends to decrease the distance you can
go by  about a third. Then you need 33% more spans to go the same distance.
Also, in order to send 25% more bits, you wind up increasing the power by
25%, and you use more optical bandwidth. And since you are sending more
bits, you are using more optical bandwidth. These facts result in fewer
optical channels being supportable on a fiber, resulting in more fibers
being used, resulting in more line systems, etc.  The result again is more
equipment and higher costs.

Actually, the electronic parts might become less expensive with the 25%
extra speed. The balanced nature of the 8B10B code decreases the cost and
attention that must be paid to jitter.

Drew
---------------------------------------------------------
Ciena Corporation                 Email: ddp@xxxxxxxxxxxx
Core Switching Division                 Tel: 408-865-6202
10201 Bubb Road                         Fax: 408-865-6291
Cupertino, CA 95014              Cell/Pager: 408-829-8298


-----Original Message-----
From: owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx
[mailto:owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx]On Behalf Of
Peter_Wang@xxxxxxxx
Sent: Friday, June 25, 1999 8:35 PM
To: rabynum@xxxxxxxxxxx
Cc: stds-802-3-hssg@xxxxxxxx
Subject: Re: Issues concerning 10GbE speed standards





Roy,

From a number of the component vendors' presentations at CFI, I don't recall
anyone claiming that the cost of the electronic parts (SiGe or GaAs) will be
much different between 10 & 12.5 Gbps.  The primary cost issue seemed that
of
the relative laser performance (e.g. temperature stablization).  Also, if
you
are talking about "converting" an existing Sonet chip to silicon (meaning
that
the existing desing is in GaAs) and throwing away a bunch of circuits, I
wouldn't be so sure that the development cost would be much less.  In any
case,
assuming the volume is large (which I'm sure everyone's hoping), the
development
cost will be amortized, and hence not a significant factor.  But this is a
discussion for LAN (or enterprise) applications.  I was trying to understand
the
economics of applying Ethernet to WAN but forcing it within the existing WAN
practice, and hoping you could provide some insight.

Peter




Roy Bynum <rabynum@xxxxxxxxxxx> on 06/25/99 04:50:23 PM

Please respond to rabynum@xxxxxxxxxxx

Sent by:  Roy Bynum <rabynum@xxxxxxxxxxx>


To:   Peter Wang/HQ/3Com
cc:   stds-802-3-hssg@xxxxxxxx
Subject:  Re: Issues concerning 10GbE speed standards





Peter,

Just because a SONET OC192C framing is used, does not mean that the OAMP
functionality is active in the LAN interface.  If OAMP processing is not
needed, only the existing SONET chip set, converted to silicon, with
most active functionality, other than path BER can be disabled.  This
will leverage the existing technology without the higher cost of the
APS, line and section overhead, etc.

Having worked on devices before, I know that the higher the bit signal
rate the more expensive the devices.  With a PHY that is 1/4 higher in
bit rate, compared the 8B/10B signal rate, the OC192 rate may be less
expensive.

Roy



Peter_Wang@xxxxxxxx wrote:
>
> It will help a great deal if you could point out specific aspects and
approaches
> where an Ethernet extended to support all of the existing common carrier
O&M
> requirements, encapsulated within the existing Sonet/SDH structure,
running
over
> existing OC192/STM64 facilities, will actually come out costing
significantly
> less that the current solution?
> - Peter
>
> Roy Bynum <rabynum@xxxxxxxxxxx> on 06/20/99 07:34:08 AM
>
> Please respond to rabynum@xxxxxxxxxxx
>
> Sent by:  Roy Bynum <rabynum@xxxxxxxxxxx>
>
> To:   wthirion@xxxxxxxxxx
> cc:   stds-802-3-hssg@xxxxxxxx, stds-802-3-hssg-speed@xxxxxxxx (Peter
>       Wang/HQ/3Com)
> Subject:  Issues concerning 10GbE speed standards
>
> Walt, et al,
>
> The issue of speed is one of economics.  The existing GbE standard does
> not allow for any operations support for the optical fiber facility.
> This makes GbE very expensive to maintain and support over a MAN/WAN
> environment.  The cost of ownership of GbE will prevent it from having a
> masive impact directly on the cost of MAN and WAN data communications.
>
> Common carrier protocols, such as DS1/DS3/SONET/SDH have operations and
> maintencance functionality incorporated in the overhead of the
> protocol.  DS1 and DS3 have a subcarrier that provides remote and
> reverse signalling outside of the transport "payload".  This allows
> carriers to troubleshoot and maintain remote systems without haveing to
> dispatch someone for every little issue.  In some respects, GbE fails to
> meet the 802.3 functional requirements for interoperation with common
> carrier systems.
>
> 1000BaseSX and 1000BaseLX are optical networking standards.  Whether
> this was the intention or even the perception of the 802.3 working
> group.  The working group did not include any support for operations or
> maintenance in the optical domain for this protocol.  The functional
> operations of copper LAN facilities are well understood by the 802.3
> working group, but when you get beyond multi-mode, 850nm, optical
> transport, it is no longer a LAN, it is a WAN.  Some will say that 30km
> is a MAN, not a WAN.  If you apply the same function processes
> distictions to optical systems that are applied to copper systems, you
> will discover that a MAN is actually a WAN within a single central
> office domain. When I was actively working on Ethernet, when it left the
> building, it was no longer a LAN, it was a WAN.
>
> In order for 10000BaseX to support MAN/WAN systems within common carrier
> facilities, common carrier operations and maintance support must be
> within the protocol.  SONET/SDH are the current, and most widely
> deployed transport protocols within the common carrier domain.
> SONET/SDH use the transport overhead to provide that functionality.
> That functionality allows the common carriers to reduce the operations
> and support costs for the fiber optic transport systems, and thus lower
> the overall costs passed on to the end users.  This will be the economic
> breaking point for 10GbE.  Can it directly support the fiber optic
> transmission system?  Is there any reason why it should not be able to
> directly provide operations support for the optical fiber systems?
>
> A second economic issue of speed for 10GbE is one of utilizing existing
> technology and standards at the ~10Gigabit speed range.  A masive
> install base of facilities and support already exist for OC192/STM64 on
> a global scale.  Optical amplifers, signal and clock recovery
> regenerators, and other systems are already in place to carry
> OC192/STM64 signals in metropolitan as well as wide are networks.  I
> would not want to contemplate the economic impact of having to install
> totally seperate technology to support 10GbE.  If it can not use the
> existing ~10Gb technology and facilities, Other than "dark fiber", 10GbE
> will have to be installed over a totaly new, and totaly seperate
> facilities.  Is there any reason why 10GbE should not support and make
> use of the existing ~10Gb transport facilities?
>
> I hope that this message has not been too long.  As an employee of a
> common carrier company, I have a recognizable vested interest in looking
> toward 10GbE as a major economical alternative to existing data tranport
> technolgy, such as TDM or ATM.  I have almost 20 years of designing,
> installing, and supporting LAN, MAN, and WAN systems.  I have seen the
> economics change as more self-supporting protocols and technologies have
> become available.  The key is to provide a protocol that allows remote
> operations support, which reduces the number of "warm bodies" that are
> required to support the systems.  This is what I am asking for.  Is
> there any reason why this can not be done?
>
>                          Thank you,
>                          Roy Bynum
>                          MCI WorldCom