[70682] in North American Network Operators' Group
Re: fiber cut 19 May/PM -> 20 May/AM in Ashburn, VA (lawnmower?!)
daemon@ATHENA.MIT.EDU (Dan Armstrong)
Fri May 21 10:03:48 2004
Date: Fri, 21 May 2004 10:03:01 -0400
From: Dan Armstrong <dan@beanfield.com>
To: "Robert E. Seastrom" <rs@seastrom.com>
Cc: nanog@merit.edu
In-Reply-To: <87fz9uq8wg.fsf@valhalla.seastrom.com>
Errors-To: owner-nanog-outgoing@merit.edu
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(Apologies to people from Eastern Canada...)
We in Canada refer to that as a "Newfie Ring".
That is just bad planning on the part of the telco. Probably due to
their size. The facilities people don't talk to, or don't like network
planning people etc. etc.
:-)
Robert E. Seastrom wrote:
>Dan Armstrong <dan@beanfield.com> writes:
>
>
>
>>Forgive me, but
>>
>>Isn't Sonet usually deployed in a ring? Why the heck would a fiber
>>this important not be?
>>
>>
>
>sonet, obviously, does not *have* to be in a ring, but it often is.
>unfortunately, a fair percentage of the time, the additional
>protection offered by a ring topology is a mirage, due to a
>configuration known as "collapsed backbone". in this instance, both
>pairs of fiber ride in the same conduit for some portion of the
>distance (most notably laterals to building entrances, but sometimes
>for a fair distance down the street). the driving factor in building
>this way is usually cost savings.
>
>while this arrangement does protect against failures of optics and
>electronics (which in fairness are indeed more common than fiber
>cuts), it provides no protection against hungry construction (or in
>this case, lawn maintenance) equipment.
>
> ---rob
>
>
>
>
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(Apologies to people from Eastern Canada...)<br>
<br>
We in Canada refer to that as a "Newfie Ring".<br>
<br>
That is just bad planning on the part of the telco. Probably due to
their size. The facilities people don't talk to, or don't like network
planning people etc. etc.<br>
<br>
<br>
:-)<br>
<br>
<br>
<br>
Robert E. Seastrom wrote:<br>
<blockquote type="cite" cite="mid87fz9uq8wg.fsf@valhalla.seastrom.com">
<pre wrap="">
Dan Armstrong <a class="moz-txt-link-rfc2396E" href="mailto:dan@beanfield.com"><dan@beanfield.com></a> writes:
</pre>
<blockquote type="cite">
<pre wrap="">Forgive me, but
Isn't Sonet usually deployed in a ring? Why the heck would a fiber
this important not be?
</pre>
</blockquote>
<pre wrap=""><!---->
sonet, obviously, does not *have* to be in a ring, but it often is.
unfortunately, a fair percentage of the time, the additional
protection offered by a ring topology is a mirage, due to a
configuration known as "collapsed backbone". in this instance, both
pairs of fiber ride in the same conduit for some portion of the
distance (most notably laterals to building entrances, but sometimes
for a fair distance down the street). the driving factor in building
this way is usually cost savings.
while this arrangement does protect against failures of optics and
electronics (which in fairness are indeed more common than fiber
cuts), it provides no protection against hungry construction (or in
this case, lawn maintenance) equipment.
---rob
</pre>
</blockquote>
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