Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: Please help to clarify some things!




Roy,

Quite a while back there was some talk on remote link down information in
802.3. If we can work that into the 10G Ethernet PHY specification, would
that satisfy your requirement? Since we don't use link pulse, may be we can
put in something in the line coding scheme to indicate remote link status?
The original remote link down function basically uses the link pulse to
inform the MAC that the up link is failing. Even if ping fails because of
failing optics on the up link, we can still get the link status on the up
link from the other MAC. What do you think?

Thanks!
Henry Ngai

----- Original Message -----
From: Roy Bynum <rabynum@xxxxxxxxxxx>
To: <mick@xxxxxxxxxxx>
Cc: <stds-802-3-hssg@xxxxxxxx>
Sent: Monday, August 30, 1999 8:25 PM
Subject: Re: Please help to clarify some things!


>
> Mick,
>
> The splice points are just physical joinings of the fiber.  The problem is
that
> they can be inconsistent to the point of effecting the functionality of
the data
> transmission.  They can also be effected by people messing with them in
the
> process of working on the fiber cable.   As a cable degrades or is damaged
the
> link level may fail to the point of not being able to use "ping", yet the
remote
> status information can inform you of whether the problem is in both
directions
> of the traffic, or just one, and which one.  A ping can not tell you if
the link
> failed in one direction only. As a transmission laser starts to fail, the
remote
> system returning its receive status information can cause an allert/trap
against
> the local system, even though the problem was seen on the remote system.
At
> present, SNMP can only tell you if there are excessive error frames.  It
does
> not have visibility at the optical level.  Having a network management
system be
> able to properly report where the problem is will save a lot of time,
effort,
> and expensive support people in the process of resolving the problem.
Part of
> what I am recommending is adding to SNMP the visibility to the optical
level.
>
> Thank you,
> Roy Bynum
> MCI WorldCom
>
> Mick Seaman wrote:
>
> > Roy,
> >
> > I'm sorry, I feel you are repeating "full duplex 10Gb 802.3 is in need
of
> > protocol
> > level operations support functionality" but not adding to my
understanding
> > of why at all. I am probably not alone.
> >
> > Can we be more specific about those things that the functionality you
> > propose will enable us to diagnose that can not be accomplished by
> > collecting data in the systems attached to the Gigabit MAC and then
sharing
> > that data or responding to queries using that MAC to transmit and
receive.
> >
> > Is it possible to see or manage the splice points you refer to using an
> > embedded protocol? I thought they were just physical splice points and
that
> > none of the protocols you were discussing contained embedded OTDR. So
the
> > only thing that would help me to manage these would be better insight
into
> > BER or 'physical' level signal conditioning at the end stations. Why
can't I
> > get at the information provided by this using SNMP, or check
connectivity
> > using 'ping' etc. etc. What is there here that needs support in the MAC?
It
> > may be that the world needs better management protocols but why is that
a
> > subject for HSSG discussion?
> >
> > Mick
> >
> > From: owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx
> > [mailto:owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx]On Behalf Of Roy Bynum
> > Sent: Sunday, August 29, 1999 10:24 PM
> > To: Henry Ngai
> > Cc: stds-802-3-hssg@xxxxxxxx
> > Subject: Re: Please help to clarify some things!
> >
> > Henry,
> >
> > In your document, your first and second drawings are somewhat correct.
I
> > doubt
> > that 10GbE would ever be implemented as you are showing it in your third
> > drawing.  In your first drawing, you need to add a fiber plant that has
> > things
> > like splice points every 5 km at most, access to the fiber cable by
people
> > that
> > have nothing to do with your data, and other issues.  The traditional
802.3
> > LAN
> > environment was outgrown when full duplex 802.3 over optical transport
was
> > standardized.  It is even possible to take full duplex 100BaseFX over
WAN
> > distances with optical converters that are sold by several different
> > vendors.
> > As seen by individuals that are attempting to create manageable
enterprise
> > level data networks with GbE, full duplex 10Gb 802.3 is in need of
protocol
> > level operations support functionality in order to grow to its true
> > potential.
>
>