[167126] in North American Network Operators' Group
Re: Is there a method or tool(s) to prove network outages?
daemon@ATHENA.MIT.EDU (Warren Bailey)
Sun Dec 1 22:09:30 2013
From: Warren Bailey <wbailey@satelliteintelligencegroup.com>
To: "Dobbins, Roland" <rdobbins@arbor.net>, "nanog@nanog.org" <nanog@nanog.org>
Date: Mon, 2 Dec 2013 03:09:13 +0000
In-Reply-To: <DE12D479-9F61-413E-BAE3-C38609B9333B@arbor.net>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Keep in mind that inter web traffic has nothing to do with the overall
health of the radio link. In RF land, we really don=B9t care what is going
over that link - just that we have enough RSL hitting the receiver to be
above threshold thus allowing the box to demodulate that signal. If your
radio is sitting at a threshold RSL of -108 and you=B9re coming in at -105,
big trouble in little China (3dB fade murdered your link). Stop thinking
like a network engineer.. If your DS-1 was taking hits, an ICMP request
(or lack thereof) would mean little (read: zero) to me as an RF Engineer.
I want to see the BER/PER of the circuit over time so I can correlate
possible trouble with real world issues.
With that being said.. the tidal issue comes up a lot, and more times than
not I see someone who said =B3Point that dish over there=B2 and when it
magically works they have earned the title of =B3Best RF Engineer in
History=B2 until the tide rolls in and their link suddenly has =B3issues=B2=
. The
invention of cheap wireless has caused many people to believe they have in
depth wireless experience, and that is usually not the case.
Not trying to preach, but I=B9ve spent a *TON* of time and other people=B9s
money in multi path land.. If someone was responsible for the proper
design of the link multi path would not be a factor as it would be
addressed early on in the link. You are not going to gain much traction
with a wireless company when you call and tell them your pings aren=B9t
working.. They are kind of like parents.. They just don=B9t understand. ;)
//warren
Ps - I welcome any replies on or off list.. I know how frustrating it can
be to have a link that seems to work well until you look at it, so I
probably have a bit more compassion than others when talking about broken
Microwave/Satellite hops.
On 12/1/13, 5:40 PM, "Dobbins, Roland" <rdobbins@arbor.net> wrote:
>
>On Dec 2, 2013, at 6:26 AM, Warren Bailey
><wbailey@satelliteintelligencegroup.com> wrote:
>
>> I would hold off on considering Multipath as a problem until you see
>>the RSL.=20
>
>Concur. It could also be related to precipitation or other adverse
>conditions.
>
>Or, in fact, it could be related to the 'UTM' box and/or something else
>on the endpoint network. It could be a periodic DDoS attack, or traffic
>causing an availability hit as an unintended consequence.
>
>It's difficult to say without data. Since the OP has the ability to
>gather IP-level data on his own network, he should utilize whatever
>instrumentation and telemetry he can set up in order to diagnose the
>issue as accurately as possible.
>
>And the OP should dig out his SLA and see what it says about the
>obligations of his upstream.
>
>-----------------------------------------------------------------------
>Roland Dobbins <rdobbins@arbor.net> // <http://www.arbornetworks.com>
>
> Luck is the residue of opportunity and design.
>
> -- John Milton
>
>
