From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from tuna.sandelman.ca (tuna.sandelman.ca [209.87.249.19]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 264BD3B29D for ; Fri, 21 Apr 2023 12:11:29 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by tuna.sandelman.ca (Postfix) with ESMTP id B130C3898C; Fri, 21 Apr 2023 12:29:04 -0400 (EDT) Received: from tuna.sandelman.ca ([127.0.0.1]) by localhost (localhost [127.0.0.1]) (amavisd-new, port 10024) with LMTP id YInh7lhEmmzB; Fri, 21 Apr 2023 12:29:04 -0400 (EDT) Received: from sandelman.ca (unknown [IPv6:2607:f0b0:f:2:40a:34ff:fe10:f571]) by tuna.sandelman.ca (Postfix) with ESMTP id D09AA3898B; Fri, 21 Apr 2023 12:29:03 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sandelman.ca; s=mail; t=1682094543; bh=UISdNocuSNy42il4D6dl+8F9eGTm2kuhTKen3aXtdmQ=; h=From:To:Subject:In-Reply-To:References:Date:From; b=wXw3ZsJLWJdkdWhDxmYz7Hmr8tdXrogGr3FtknmZnfKygglJynR/FpPovnDomn5W8 1T4p/kD2beC4KveKsPJOelLA2AIiBJBBDGzq/siykIhviyumVpeNOlvcP5n5sQGjYd aGB4UCO75oURpFPTe8DMqJlyY4Z5vYzyobNI01vxcxyDn3yFBU0RJ1KDW4yrUTAWAX rw1R7pUp+x8Xiq/X6qZ9NevpPA3Rs8oAUclZzJ+nmC7Vw8k1jXeass/lWPhJqRauUL 01VEscHIAl/9cFQmCAA2NIAjJT8GKCAoo4pMFXdvJ8rQhQuQClvP5AzKllfZWOxJSI 0A6CPdZuLPQEA== Received: from localhost (localhost [IPv6:::1]) by sandelman.ca (Postfix) with ESMTP id 6C85D1F8; Fri, 21 Apr 2023 12:11:27 -0400 (EDT) From: Michael Richardson To: Ulrich Speidel , "starlink@lists.bufferbloat.net" In-Reply-To: References: X-Mailer: MH-E 8.6+git; nmh 1.7+dev; GNU Emacs 27.1 X-Face: $\n1pF)h^`}$H>Hk{L"x@)JS7<%Az}5RyS@k9X%29-lHB$Ti.V>2bi.~ehC0; <'$9xN5Ub# z!G,p`nR&p7Fz@^UXIn156S8.~^@MJ*mMsD7=QFeq%AL4m Subject: Re: [Starlink] Starlink in Kiribati X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Apr 2023 16:11:29 -0000 --=-=-= Content-Type: text/plain Ulrich Speidel via Starlink wrote: > All traces (to NZ, Chile, the US, Germany and Japan) exited the SpaceX > address space in New Zealand to a variety of upstream providers. IP > addresses on the Starlink side of the trace beyond Dishy are, in order of > appearance in the traces: 100.64.0.1, 172.16.249.6, followed by 149.19.109.30 > if exiting to Hurricane Electric as upstream or 149.19.109.34 if exiting to > Kinect. All those addresses have RTT indicating that they are in NZ. What are you being NAT44'ed to? Presumably, that IP is in NZ, and you could traceroute/ping back to it from elsewhere to be able to subject whatever congestion is beyond the peering point. > Lowest RTT seen to the first NZ hop was 65 ms, with values between 100 and > 200 ms being the most common. > RTTs to the US were mostly in the high 200 ms. > 2) The fact that we don't see more than the "usual" number of Starlink IP > addresses in the tracreroutes indicates that whatever IP routing may be > happening on satellites that handle the traffic via ISLs happens at a tunnel > layer further down the stack. Given Musk's age old tweet that it was "simpler than IPv6", and that we know that it's some kind of broadcom SDN chipset, this makes sense. I wish they had used SR6, and done IPv4 as a service. > 3) The fact that the traffic emerges in New Zealand regardless of global > destination also indicates that the Starlink network uses a tunnel based > on Dishy location and a nearby gateway but does not attempt to route to final > destination at this point in time. I'm not surprised about this. I don't imagine they can world-wide stuff until all the non-ISL birds have aged out. > The 65 ms RTT also tells us a few things. For one, at 4,200 km great circle > distance on the ground, the dishy-to-gateway physical path would be at least > 5,000 km even if all lined up with a polar orbital plane involved. That makes > 10,000 km of RTT path, which translates into about 33 ms of propagation > RTT. If cross-plane routing were involved here, we'd get a zig-zag path - so > roughly 1 1/2 times longer. Makes about 50 ms. In-plane only routing would > involve a gateway in Australia (similar length physical path dishy to > gateway) along with a 2,000 km trans-Tasman cable leg. The 2000 km cable leg > would be equivalent to about 20 ms of additional RTT over the 10,000 km space > RTT path, so that could in principle also work. Quite why everything would > emerge in Auckland though in this case would be a mystery to me. I think you are saying that the your lowest RTT of 65ms is easily supported by physical distances alone? And that it can't get better. --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQFFBAEBCgAvFiEEbsyLEzg/qUTA43uogItw+93Q3WUFAmRCta8RHG1jckBzYW5k ZWxtYW4uY2EACgkQgItw+93Q3WWogwf+M5xH7r6wSKPZeVcOO29olTxo4toJgbKj 0ovkNTkiTRLPx7tApMt3bCv6zxeMv1SpRoLo4R1+AejaCr+7Vvrt8zPmU99PH2mT lzibFzcXKb3nyrabZ9NbzBChfU+5pNOO50J2u+bYKzyjP1C7vDJz6ddeQTrGkmtQ eeFs19l3UqOSvpSeaLSp4E7zMvsimyPje29iQbMgOyVHOegtEuBH8yVu9n3x5OYL oPHcEDP1qyXkeJdg1vOsYFEISkIeNmffAfl5356Ol01MwKd5p/0QAyOgUX5cdopU EBpuiMPJ12bInAjVxilZkRyltDMrtREVj1TRrI7a8rfZ6Pk92jubow== =YULm -----END PGP SIGNATURE----- --=-=-=--