[195867] in North American Network Operators' Group
Re: 100G QSFP28 DAC cables - experience
daemon@ATHENA.MIT.EDU (joel jaeggli)
Tue Sep 19 04:47:46 2017
X-Original-To: nanog@nanog.org
To: Jiri Prochazka <jiri@cdn77.com>, nanog@nanog.org
From: joel jaeggli <joelja@bogus.com>
Date: Mon, 18 Sep 2017 14:03:43 -0700
In-Reply-To: <c8680f47-f195-7c01-b75b-2a4ff4505e63@cdn77.com>
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From: joel jaeggli <joelja@bogus.com>
To: Jiri Prochazka <jiri@cdn77.com>, nanog@nanog.org
Message-ID: <a3c36ce6-c34c-530a-879a-fef0083b0a74@bogus.com>
Subject: Re: 100G QSFP28 DAC cables - experience
References: <c8680f47-f195-7c01-b75b-2a4ff4505e63@cdn77.com>
In-Reply-To: <c8680f47-f195-7c01-b75b-2a4ff4505e63@cdn77.com>
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On 9/6/17 00:17, Jiri Prochazka wrote:
> Hi folks,
>
> I'm wondering if anyone have (either positive or negative) experience
> with 100G QSFP28 DAC cables?
I found the ones we tested to be substantially more finicky particularly
at 5 meter then 10gig dacs, adding 4 x 25 sfp28 breakout on the other
end probably isn't a help. We went with AOCs for the equivalent (3, 5
meter) lengths.
> Is there anyone who is using 100G DAC in large scale and would
> recommend it (which means there are no issues compared to SR4 links)?
>
> I'm thinking about cables with lenght up to 1m, not more.
>
> We have had quite bad experience with 10G DAC in the past - but I do
> not want to be slave of the past.
>
>
10g dacs were less reliable then I would have preferred for=A0 3 5 7 mete=
r
distances but they were tolerable especially if you leave the bundles
alone, 25g was sufficiently less so at least in testing that we didn't
try it in the field, being at the limits at 5m was a sufficient
problemthat it ruled out some adjacent rack arrangements. so we're all
optical for 25/100
>
> Thank you for your thoughts!
>
>
>
> Jiri
> =A0=A0=A0=A0
>
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