[178785] in North American Network Operators' Group
Re: mpls over microwave
daemon@ATHENA.MIT.EDU (Bryan Fields)
Fri Mar 6 10:41:33 2015
X-Original-To: nanog@nanog.org
Date: Fri, 06 Mar 2015 10:41:23 -0500
From: Bryan Fields <Bryan@bryanfields.net>
To: "nanog@nanog.org" <nanog@nanog.org>
In-Reply-To: <WM!31449708da42fb8f2422ac123c8fc167dc21bd09c01ae6a4f47e19b0b9f64dcf3f29c8dd7426f34e97e0017bdc998ca2!@asav-1.01.com>
Errors-To: nanog-bounces@nanog.org
On 2/6/15 11:32 AM, Donn Lasher wrote:
> Properly engineered, however, is the key. Make sure whom-ever is building
> your links looks at vendor specs, builds a real link budget (including
> losses from connectors, cable, grounding, etc) properly weather seals
> everything, and try to get at least a a 20db fade margin if you can. If
> the things I just mentioned are confusing to your RF guy, you might want
> to get outside help.
Make sure they can know the models for propagation as well. At lower bands
fading caused by K factor change can be a bitch and is the predominant mode of
fading. on the higher bands (>11GHz) rain fade is the predominant mode of fading.
If you want your network to have 99.999% uptime, the links need to be
engineered for 99.9999% uptime.
Make sure the consultant knows Pathloss5 and is not using a vendor's program
for that (orthogon/motorola/cambium/whatever they call them now) loves to push
their own shitty program.
If you're using a dynamic data rate radio (most are), ensure you engineer for
highest data rate you need. If you run the calcs and it shows 99.9999999% at
bfsk but you need 128qam to get your full data rate, what good is it?
congestion do to link down modulation is still an outage.
--
Bryan Fields
727-409-1194 - Voice
727-214-2508 - Fax
http://bryanfields.net
