Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.


dreamtype

46 posts

Geek


#21106 15-Apr-2008 22:19
Send private message

if you get too many tcp retransmissions to 1 destination,is it bad?what causes tcp retransmissions?what are the consequences?solution?

Create new topic
d3viant
7 posts

Wannabe Geek


  #123869 15-Apr-2008 23:01

If the host your communicating with sends you 4 packets with sequence #'s 10,11,12,13 if you successfully receive all data, the client sends an ACK back with sequence#14 (the next number), if the last two packets were dropped along the way or were corrupted the client would send an ACK back with seq#12 (signaling that it only received 10 & 11) this would then que the host to do a re-transmission of #12,13.  Yes it's bad, because tcp is inherently a latency laden protocol.  There's multiple causes, mostly network congestion.

foobar
186 posts

Master Geek


  #123888 16-Apr-2008 04:17
Send private message

Different stages of a TCP connection will have different retransmission strategies and timeouts. For example, during the three-way handshake at the start of the connection, the retransmission characteristics are different than later in the connection.

Are you seeing the retransmission in data coming to you or being sent from you? Is this during the bulk data transfer, or during connection establishment/termination handshake?

For example, during the initial handshake, you may see multiple SYN+ACK packets from the server you are trying to connect to. Some TCP stacks have very aggressive retransmission at that stage. If you see a couple of those, especially if you are talking to a server on the other side of the globe, you have absolutely nothing to worry about. That's still quite normal.

If you are looking at the bulk transfer, and you see retransmission of some of the larger data packets then this indicates a pipeline-stall: The sending side had to stop streaming its data and retransmit. Normally, TCP will try to avoid that and tunes its send and receive windows to that end. Having retransmission occur anyway at that stage probably indicates intermittent packet loss or delay, caused by congestion somewhere along the way.

Create new topic





News »

Nanoleaf enhances lighting line with launch of Triangles and Mini Triangles
Posted 17-Oct-2020 20:18


Synology unveils DS16211+
Posted 17-Oct-2020 20:12


Ingram Micro introduces FootfallCam to New Zealand channel
Posted 17-Oct-2020 20:06


Dropbox adopts Virtual First working policy
Posted 17-Oct-2020 19:47


OPPO announces Reno4 Series 5G line-up in NZ
Posted 16-Oct-2020 08:52


Microsoft Highway to a Hundred expands to Asia Pacific
Posted 14-Oct-2020 09:34


Spark turns on 5G in Auckland
Posted 14-Oct-2020 09:29


AMD Launches AMD Ryzen 5000 Series Desktop Processors
Posted 9-Oct-2020 10:13


Teletrac Navman launches integrated multi-camera solution for transport and logistics industry
Posted 8-Oct-2020 10:57


Farmside hits 10,000 RBI customers
Posted 7-Oct-2020 15:32


NordVPN starts deploying colocated servers
Posted 7-Oct-2020 09:00


Google introduces Nest Wifi routers in New Zealand
Posted 7-Oct-2020 05:00


Orcon to bundle Google Nest Wifi router with new accounts
Posted 7-Oct-2020 05:00


Epay and Centrapay partner to create digital gift cards
Posted 2-Oct-2020 17:34


Inseego launches 5G MiFi M2000 mobile hotspot
Posted 2-Oct-2020 14:53









Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.


Support Geekzone »

Our community of supporters help make Geekzone possible. Click the button below to join them.

Support Geezone on PressPatron



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.

Alternatively, you can receive a daily email with Geekzone updates.