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CAT:NONE; SFS:(396003)(136003)(366004)(39850400004)(346002)(376002)(8936002)(966005)(956004)(6916009)(66476007)(2616005)(33964004)(31696002)(26005)(52116002)(36916002)(86362001)(6486002)(16526019)(186003)(5660300002)(8676002)(66556008)(66946007)(31686004)(478600001)(36756003)(166002)(2906002)(316002)(83380400001)(16576012)(3450700001)(83080400001)(43740500002); DIR:OUT; SFP:1102; X-MS-Exchange-AntiSpam-MessageData: vSk1M+zhdEP+63u/v89KD4laihksGaHceNoQeXFxwm1tdBuWOMShc5nryX0G8Ou9a2ukXboq2tD61jMf3zhqmwPeTthL0XgBK7NQmfrUpKa12DErf0V6iPaNcM2FoBzzL8mIT5VB00hkjbEMwubGTwx2fkrRj4OCDWa0DxVKS56YIcq9/XnJejUTXH/ne2/2DmxYUTCx1g+Av0xA+YNet5yH26klJxSk1EPE7s8mjOjsy1uajOPdhRGXM65yQAiFw1dzUcW7ldZv7gZDQp5up59v9KRm/LLZQhb5sUE5WB4Ltz8ZDSgAPzAZDbqoV3KwydV0PuBg2pFw3vmg8kUaqwDK7iCwgroEMLPAhQVuNZ9d4jXwOx9xlZFEoPGDZn7/MJ50E9mU7UW03uwp3Kvtf6pGkCe1A8UEHi2XlIis4CRFW+/SN5yTu6Uv5el8oVTPvNxXrtfZP0BFlbwfMBPcyeTN1x8Vqv0vRhjwrbxw/cgGvv7yf+Muae+KiyTvFw6CBWITj7VpEr+6hPN7H7XCW0A17EENkIMQLlshrPoHPqt/LPaRbllcLINZNQVPXvD94T3PybTnFOStMPqsCk6g9SHgYmU8nmpIhxq/pQCEShjITN+zvr4Qc4nMKrtJywN6iUunU0AF1G7QNDmE2AH4UA== X-OriginatorOrg: indexexchange.com X-MS-Exchange-CrossTenant-Network-Message-Id: 8bd58ce9-3f5d-48e3-f235-08d86953d60e X-MS-Exchange-CrossTenant-AuthSource: YQXPR01MB3925.CANPRD01.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Oct 2020 17:26:46.8260 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: b07c0690-22b8-4366-8d8d-7b845d088e18 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: qwo4VZeJZF/6ojdv+8xUAf1JkwoiEQcZDcMt70B9cUt6PEJve/bFyHHTgGSroVC6CImUYDPpJANQdwgrPpjxsCroKnVle2KT3Zk3FlHh2GxTJIFiqLO/OpyaP75eKUvQ X-MS-Exchange-Transport-CrossTenantHeadersStamped: YQBPR0101MB1636 Subject: [Bloat] An interesting, and probably erroneous, article on 5G and TCP buffering 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: Mon, 05 Oct 2020 17:26:59 -0000 --------------5C47EE9D877B32CF44ABF13D Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: quoted-printable In "the morning paper", https://blog.acolyer.org/2020/10/05/understanding-o= perational-5g/, reviewing http://xyzhang.ucsd.edu/papers/DXu_SIGCOMM20_5Gme= asure.pdf With TCP the story is less compelling, with common congestion control algor= ithms not suiting 5G characteristics Traditional loss/delay based TPC algorithms suffer from extremely low bandw= idth utilization =E2=80=93 only 21.1%, 31.9%, 12.1%, 14.3% for Reno, Cubic,= Vegas, and Veno, respectively! Only being able to use 20% of the bandwidth is clearly not good (on 4G the = same algorithms achieve 50-70%). BBR does much better with 5G, achieving= 82.5% utilization. An investigation reveals the problem to be caused by bu= ffer sizes. In the radio portion of the network, 5G buffer sizes are 5x 4G,= but within the wired portion of the network only about 2.5x (this is with = a 1000 Mbps provisioned cloud server). At the same time the download capaci= ty of 5G is about 5x greater: "i.e., the capacity growth is incommensurate = with the buffer size expansion in the wireline network." Doubling the wirel= ine buffer size would alleviate the problem. BBR does better because it is = less sensitive to packet loss/delay. -- David Collier-Brown, | Always do right. This will gratify System Programmer and Author | some people and astonish the rest dave.collier-brown@indexexchange.com | -- Mark Twain CONFIDENTIALITY NOTICE AND DISCLAIMER : This telecommunication, including a= ny and all attachments, contains confidential information intended only for= the person(s) to whom it is addressed. Any dissemination, distribution, co= pying or disclosure is strictly prohibited and is not a waiver of confident= iality. If you have received this telecommunication in error, please notify= the sender immediately by return electronic mail and delete the message fr= om your inbox and deleted items folders. This telecommunication does not co= nstitute an express or implied agreement to conduct transactions by electro= nic means, nor does it constitute a contract offer, a contract amendment or= an acceptance of a contract offer. Contract terms contained in this teleco= mmunication are subject to legal review and the completion of formal docume= ntation and are not binding until same is confirmed in writing and has been= signed by an authorized signatory. --------------5C47EE9D877B32CF44ABF13D Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable

In "the morning paper", https://blog.acolyer.org/2020/10/05/understanding-operational-5g/, revi= ewing http://xyzhang.ucsd.edu/papers/DXu_SIGCOMM20_5Gmeasure.pdf

With TCP the story is less compelling, with common congestion control algorithms not su= iting 5G characteristics

Traditional loss/delay based TPC algorithms suffer from extremely low bandw= idth utilization =E2=80=93 only 21.1%, 31.9%, 12.1%, 14.3% for Reno, Cubic,= Vegas, and Veno, respectively!

Only being able to use 20% of the bandwidth is clearly not good (on 4G the = same algorithms achieve 50-70%). BBR does much better with 5G, achieving 82.5% utilization. An investigation reveals= the problem to be caused by buffer sizes. In the radio portion of the netw= ork, 5G buffer sizes are 5x 4G, but within the wired portion of the network= only about 2.5x (this is with a 1000 Mbps provisioned cloud server). At the same time the download capacit= y of 5G is about 5x greater: "i.e., the capacity growth is incommensurate with the buffer size expansion in th= e wireline network." Doubling the wireline buffer size would alle= viate the problem. BBR does better because it is less sensitive to packet l= oss/delay.

--=20
David Collier-Brown,         | Always do right. This will gratify
System Programmer and Author | some people and astonish the rest
dave.collier-brown@indexexchange.com |              -- =
Mark Twain

CONFIDENTIALITY NOTICE AND D= ISCLAIMER : T= his telecommunication, including any and all attachments, contains confiden= tial information intended only for the person(s) to whom it is addressed. Any dissemination, distribution, copying or discl= osure is strictly prohibited and is not a waiver of confidentiality. If you= have received this telecommunication in error, please notify the sender im= mediately by return electronic mail and delete the message from your inbox and deleted items folders. This tel= ecommunication does not constitute an express or implied agreement to condu= ct transactions by electronic means, nor does it constitute a contract offe= r, a contract amendment or an acceptance of a contract offer. Contract terms contained in this telecommunication ar= e subject to legal review and the completion of formal documentation and ar= e not binding until same is confirmed in writing and has been signed by an = authorized signatory.

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