From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-x22b.google.com (mail-wm0-x22b.google.com [IPv6:2a00:1450:400c:c09::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id CEEFA3B260 for ; Wed, 26 Oct 2016 10:49:55 -0400 (EDT) Received: by mail-wm0-x22b.google.com with SMTP id d128so89115547wmf.1 for ; Wed, 26 Oct 2016 07:49:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding; bh=7hGfrPFWVVrzKSVJs8YUpwNHp37TtV/4CU/wGwd9T40=; b=eoB+JXIMs+qc1nayuSyw/I10zkoWiYNQydthmNUAP4ej9uYAZ0p43V7pcTvTQnq8gm O35rqo8GCL1QC1uz2oZHz4wpLJtVssfE2O3ay+3phTqn3xYA5B6CLtBJ2MumfwyTxh5X 0hPKR7KGbfOlgQX12nwqHD3/T7A2DLtv9DPJgoQvXQ7QkF7FdwzxM4qhoSfKRJEdI2iY JCnctQavqz3PB+1YukfR6ELRn/H2xV6JRtv15mjuHGG6SFd16MbGDltWZ9KTJE1dIXAD 3OpCqYhdeFrGF2k9q3A36/kmONPdc6yarGPYHN6xHc+u4blUKOMbXAgEHljxNhHeHYra 83ow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=7hGfrPFWVVrzKSVJs8YUpwNHp37TtV/4CU/wGwd9T40=; b=moBpAZrdQgwsDMtOlIxGvvNYfLNych2QKPPwj4AmG0NDKFcO35x/NuyoQ5IUA1PE1R Wz9xUadFPrp9MMjWqRw59MOzdIqs6QSAiW2h3WFhqi8X25LX8wV6sMOdlUsIZUkuOFMf Bja1UKLOuqlMvyWF6GjvQExFUlKh2lhA81FxwpyDi8zZm/FSfN/yvxzVpWV/lakRHpxv +LXIoNH+IGOZCZRffysbrYbNXjTZDl0QSF1yR6WcjxBN7nanP8OfQYz03dg68djWWmb9 32YT4OfDWuRyYv+BRQyeidvaXkXtkdZuaYKd+4TexVrIXvqKqAsj4hDZDoseEvlMuJZX OiwA== X-Gm-Message-State: ABUngvdznsyw5ROUak+Xg5ADkCeI2nEdf5nyrEVA2LCHzJbiGdx3tMyJrmB60vQ5CR1Y6A== X-Received: by 10.194.222.225 with SMTP id qp1mr2606151wjc.161.1477493394389; Wed, 26 Oct 2016 07:49:54 -0700 (PDT) Received: from zotac.xperim.be ([91.177.64.31]) by smtp.gmail.com with ESMTPSA id g9sm3053785wjk.25.2016.10.26.07.49.53 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 26 Oct 2016 07:49:53 -0700 (PDT) Received: from [192.168.1.172] (mordor.xperim.be [192.168.1.172]) by zotac.xperim.be (Postfix) with ESMTPSA id 661A949617B; Wed, 26 Oct 2016 16:49:52 +0200 (CEST) To: Benjamin Cronce References: <5a2d4224-3f4e-80f0-3b0b-b2fbbdd59697@gmail.com> Cc: bloat From: Jan Ceuleers Message-ID: <77a4abf0-bc94-0d2e-eebe-d72e2e676255@gmail.com> Date: Wed, 26 Oct 2016 16:49:52 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Bloat] 22 seconds til bloat on gfiber? X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Oct 2016 14:49:56 -0000 On 26/10/16 03:05, Benjamin Cronce wrote: > Sorry to side track > > 1:1 split bandwidth wise, still a 1:16 or whatever fiber split. Each > port can handle 40Gb/s, which is 32 lambdas of 1.25Gb/s, each customer > getting their own lambda. The ONT can either be WDM-PON or GPON with an > inline filter. A Google Fiber engineer actually had this in his blog a > long while back, talking about their design and the "dedicated" aspect > of an unshared GPON. PON can only handle about a 32 split before the > signal strength gets too low toe be practical. If each group of > customers shared a lambda, they would need too many split or repeaters, > which is more impractical. I am aware of GPON deployments with splitting factors of 64 and higher, and these do not (at all) pose a problem with the optical power budget. > I'm not entirely sure which part you mean "impractical". What I mean is that the OLT optics become very expensive if you need to support as many lambdas as you have customers. You'd furthermore need an OLT port for much fewer customers (e.g. 1 port per 64 or 128 customers) than the thousands you can support on a (shared) GPON port on a single lambda. Also on the ONT side there is the danger of spiraling cost in that I don't think it is economically feasible yet to incorporate tunable lasers in the CPE, certainly not across 64 or 128 lambdas, meaning that you'd need as many hardware variants of the ONT as you have lambdas. But maybe I'm wrong.