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2023-05-29 02:43:48 +0000 received badge  Critic (source)
2023-04-14 19:18:11 +0000 commented answer fortigate ip connection

A clue that the client isn’t receiving the server’s Resets is the doubling of the time between successive client FIN pac

2023-04-13 03:42:05 +0000 commented question SMB2 copy issue and SRT

I agree, I'd love to see the PCAPs for these transfers so that we could see exactly what is going on. I would like to s

2023-03-21 23:32:35 +0000 edited answer slow transfer in one direction

[Edit] Note: This answer applies to the newer "dest" and "src" PCAPs. The behaviour there is very, very different than

2023-03-21 11:32:47 +0000 answered a question slow transfer in one direction

After a quick look at your "dest" and "src" PCAPs, I can see that the slow throughput is due to the sender going into co

2023-03-21 01:38:41 +0000 commented answer Packet Loss Question

To further Sake's answer: Are the packets in each capture different sizes? The 120K packets may be larger than 1460 (d

2021-04-08 05:39:33 +0000 edited answer macOS SMB uploads to Windows Server share hang for dozen of seconds

Edit 2: It's interesting how "sleeping on it" can make things clearer in one's mind. I now do think that there is a bug

2021-04-08 05:35:20 +0000 edited answer macOS SMB uploads to Windows Server share hang for dozen of seconds

Edit 2: It's interesting how "sleeping on it" can make things clearer in one's mind. I now do think that there is a bug

2021-04-06 07:11:42 +0000 edited answer macOS SMB uploads to Windows Server share hang for dozen of seconds

I don't think there's a bug with SACK behaviour. It looks like a group of 12 packets got lost after the sniffer saw the

2021-04-05 06:57:18 +0000 commented answer macOS SMB uploads to Windows Server share hang for dozen of seconds

I don't think there's a bug with SACK behaviour. It looks like a group of 12 packets got lost after the sniffer saw the

2020-10-01 06:35:46 +0000 commented question Analysing pcap

Sounds like a homework exercise.

2020-09-14 11:27:57 +0000 commented answer TCP/TLS Dropped packets, I don't know where to look for the issue?

So my guess is that only full-sized packets were dropped by the VPN endpoints - and that's why you had an apparently int

2020-03-17 01:39:16 +0000 commented answer What causes retransmissions?

True, but a capture will help you eliminate "network" causes. It can also tell you that performance issues are inside a

2020-03-11 04:02:55 +0000 commented answer What causes retransmissions?

That's a good question, given that you are directly connected. A capture would prove the TCP "congestion" hypothesis a

2020-03-09 03:35:42 +0000 edited answer What causes retransmissions?

This is probably due to packet loss in your "slow" direction - but no loss in your "fast" direction. The TCP "Congestio

2020-03-09 03:34:50 +0000 received badge  Rapid Responder (source)
2020-03-09 03:34:50 +0000 answered a question What causes retransmissions?

This is probably due to packet loss in your "slow" direction - but no loss in your "fast" direction. The TCP "Congestio

2020-03-05 06:46:28 +0000 edited answer Duplicate ACK and TCP Retransmission

Your original "AIX-to-Cloud" capture file is made more difficult to analyse due to the fact that there are a lot of pack

2020-03-05 06:28:51 +0000 received badge  Rapid Responder (source)
2020-03-05 06:28:51 +0000 answered a question Duplicate ACK and TCP Retransmission

Your original "AIX-to-Cloud" capture file is made more difficult to analyse due to the fact that there are a lot of pack

2019-12-20 08:03:13 +0000 received badge  Commentator
2019-12-20 08:03:13 +0000 commented answer comparison between two capture

I just added a couple of paragraphs referring to those server "Dup-ACKs".

2019-12-20 08:02:23 +0000 edited answer comparison between two capture

I see the throughput in both these captures to be very similar. "fast" achieves around 1.6 Mbps, with bytes-in-flight (

2019-12-18 08:49:03 +0000 edited answer comparison between two capture

I see the throughput in both these captures to be very similar. "fast" achieves around 1.6 Mbps, with bytes-in-flight (

2019-12-18 08:24:43 +0000 answered a question comparison between two capture

I see the throughput in both these captures to be very similar. "fast" achieves around 1.6 Mbps, with bytes-in-flight (

2019-12-18 08:06:58 +0000 received badge  Enthusiast
2019-12-15 10:59:43 +0000 commented answer Out of order impact?

That's a good point @SYN-bit. Yes, that could cause a performance hit.

2019-12-15 07:58:43 +0000 answered a question Out of order impact?

The receiving device will put the packets back into the correct order before extracting the data and passing it up t the

2019-05-02 00:26:49 +0000 commented question Low throughput between vmWare hosts in vxlan topology - spurious retransmissions.

This is a very interesting case study. The underlying problem is that your servers begin to "misbehave" once throughput

2019-05-02 00:25:50 +0000 commented question Low throughput between vmWare hosts in vxlan topology - spurious retransmissions.

This is a very interesting case study. The underlying problem is that your servers begin to "misbehave" once throughput

2018-12-21 12:34:05 +0000 received badge  Necromancer (source)
2018-12-21 07:56:52 +0000 edited answer How to determine throughput/bandwidth from a capture (as used in TCP window scaling)

Your throughput limitation isn’t related to Receive Window sizes (or network bandwidth limits). It is entirely limited

2018-12-21 07:49:44 +0000 answered a question How to determine throughput/bandwidth from a capture (as used in TCP window scaling)

Your throughput limitation isn’t related to Receive Window sizes (or network bandwidth limits). It is entirely limited

2018-12-11 07:58:08 +0000 edited answer Excessive TCP Dup ACK and TCP Retransmissions

There's a very consistent regularity to the way the packets flow from the client to the server. A particular pattern is

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2018-12-07 08:27:55 +0000 commented answer TCP Slow Start Graph

I created four Tweets containing charts (not created with Wireshark though). They might help to clarify the TCP and pac

2018-12-07 06:45:35 +0000 commented answer TCP Slow Start Graph

You are sending packets into your router at local LAN speed but the router can only send them to the Internet at 1 Mbps.

2018-12-07 06:44:50 +0000 commented answer TCP Slow Start Graph

You are sending packets into your router at local LAN speed but the router can only send them to the Internet at 1 Mbps.

2018-12-07 06:44:17 +0000 commented answer TCP Slow Start Graph

You are sending packets into your router at local LAN speed but the router can only send them to the Internet at 1 Mbps.

2018-12-07 05:39:11 +0000 received badge  Editor (source)
2018-12-07 05:39:11 +0000 edited answer Excessive TCP Dup ACK and TCP Retransmissions

There's a very consistent regularity to the way the packets flow from the client to the server. A particular pattern is

2018-12-07 05:34:35 +0000 received badge  Rapid Responder (source)
2018-12-07 05:34:35 +0000 answered a question Excessive TCP Dup ACK and TCP Retransmissions

There's a very consistent regularity to the way the packets flow from the client to the server. A particular pattern is

2018-12-07 04:38:14 +0000 commented question Excessive TCP Dup ACK and TCP Retransmissions

The 3-way handshake in the sender capture tells us that the AIX sender doesn't support SACK. It's possible that SACKs m

2018-12-07 03:11:13 +0000 commented question Excessive TCP Dup ACK and TCP Retransmissions

The 3-way handshake in the sender capture tells us that the AIX sender doesn't support SACK. However, SACKs may not hel

2018-12-06 08:03:25 +0000 commented answer TCP Slow Start Graph

This is great example of a downstream bottleneck (1 Mbps) with a limited buffer queue (roughly 100 KB). As the packets

2018-12-06 07:58:19 +0000 commented answer TCP Slow Start Graph

This is great example of a downstream bottleneck (1 Mbps) with a limited buffer queue (roughly 100 KB). As the packets

2018-12-06 07:27:06 +0000 commented answer TCP is limiting the use of bandwidth

You may be right @Christian_R, but the more I look at these trace files, the more I'm convinced that it is an applicatio