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19 votes
Accepted

Internet Cable Has Been cut in two and taped back together

This can introduce a number of problems, like additional attenuation or cross talk. Splicing is to be avoided whenever possible, but I have seen this work in a pinch although I would never recommend ...
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16 votes
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How can a processor handle 10 Gigabit per second or more data rate?

You are totally correct, if we have to use an instruction cycle per bit then 10Gbps would be unachievable. So the first thing to note is that we handle a word per CPU instruction -- 64 bits. Even ...
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9 votes
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iperf: send specific volume?

The -l option is for the buffer and doesn't influence the amount of data transferred. You have to specify the desired amount of data with the client-only option -n in KByte or MByte. So for 10GB, ...
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  • 18.3k
8 votes
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Is the Slow-Start algorithm responsible for ISP speed throttling?

Short answer: No, ISPs do not use TCP Slow-Start as the main way to throttle customer bandwidth. Long answer: There are many ways that an ISP can throttle the bandwidth a particular customer gets ...
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  • 8,258
8 votes

Speed benefits when switching from 1Gb copper LAN to Fiber Optic

You are conflating many things here, so let's try to detangle the issues in your question. Data rate is data rate, regardless of the physical medium. A 1Gb connection has the same data rate whether ...
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8 votes
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Cisco Router (ISR4221) Throughput - Why so slow?

That's by product design. ISR 4k come with a platform shaper (upgradeable to ~2x the value by license upgrade with the "PERF" license). Cisco say that the limits of the platform shapers can be fully ...
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8 votes

Why is microwave faster than infrared as a transmission medium?

Faster in terms of propagation delay? @Zac67 answer is good. Faster in terms of data throughput? Here, infrared has a huge theoretical advantage. The whole microwave range consists of about 300GHz ...
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  • 169
7 votes
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how to make udp reliable

UDP by itself isn't reliable. The data acknowledge/retransmission functions have to occur at a higher (i.e. application) level. TFTP is a good example of that.
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7 votes

Why is microwave faster than infrared as a transmission medium?

I've read that microwave is a faster medium of transmission of data than infrared. It's not. Light moves at the speed of light (c0), (pretty much) regardless of its wavelength - in reference to the ...
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  • 69.7k
7 votes

Why is microwave faster than infrared as a transmission medium?

Given the context which is severely outdated when not completely false, "infrared" seems to mostly refer to short-range low-bandwidth infrared communications as used: In many TV remote ...
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6 votes
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Will cutting a 50m CAT6 cable in half achieve a gigabit connection?

Cat6 can provide Gigabit speeds up to 90+ meters. It is far more likely that one of the terminations is the problem. Gigabit requires the use of all 8 wires, so if one (or both) of the terminations ...
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  • 26.7k
6 votes

The recommended settings for giga ethernet connected to Ethernet port

In reality, the legacy 10 Mbps ethernet interface probably can't negotiate, and it can probably only do half duplex (very few 10 Mbps interfaces can do full duplex). You should let the 1 Gbps ...
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  • 93k
6 votes
Accepted

Better throughput with 100 Mb NIC setting

This is a buffering issue. I had the same problem with a new Level 3 circuit. Their NID apparently has no measurable buffers, so feeding it at a rate 10x the circuit rate (1000 vs. 100) leads to all ...
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  • 29.5k
6 votes
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Fiber to copper conversion, what are the odds?

Fiber media converter is a small device with two media-dependent interfaces and a power supply, simply receive data signals from one media, convert and transmit them to another media. It can be ...
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  • 1,700
5 votes
Accepted

The recommended settings for giga ethernet connected to Ethernet port

The very short answer: don't configure anything. Auto negotiation (or the lack thereof as Ron's detailed) works only when it's left alone. Manual settings can very easily cause problems either right ...
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  • 69.7k
5 votes

Fibre vs Copper short Distance

The equipment interfaces determine the speed, albeit the medium used may have restrictions on which interfaces it can be used. If you have 1 Gbps ethernet, it doesn't matter if it is copper or fiber, ...
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  • 93k
5 votes
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Will the data transfer with the destination on the same LAN network be routed through the internet when the WAN IP is used?

I assume you're talking about a structure like this: F | ISP | R S | | ===+===+===+=== | C If your router supports so-called "hairpin routing" (or "hairpin ...
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  • 15.9k
5 votes

Relationship between full duplex and speed

Full-duplex data transmission means that data can be transmitted in both directions on a signal carrier at the same time. That is incorrect. It means devices can transmit and receive at the same ...
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  • 62.1k
5 votes
Accepted

Static speed and duplex/no-negotiate causing input error

If you disable Auto Negotiation (AN) you need to make sure that both sides are configured in exactly the same way. There's isn't any point in doing that manually, actually, so you should have AN ...
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  • 69.7k
4 votes

How do cable internet providers limit user bandwith?

The DOCSIS Service Profile within the configuration downloaded when it registers on the network tells the modem (and headend) how much bandwidth an individual modem is allowed. Exactly how the modem (...
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  • 29.5k
4 votes

how to make udp reliable

While UDP is not reliable, a lot of protocols use it as a base and add reliability at application level. You would determine what features you would need, and what you would implement: Connection ...
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  • 141
4 votes
Accepted

What does "rate 10000 cir 0" mean on an alcatel device?

User Teun Vink is very correct in his assertion that context is required, mainly in the platform that you are using and the configuration that the rate is being applied to, whether QoS or service ...
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4 votes

Is the Slow-Start algorithm responsible for ISP speed throttling?

@Machinarius, @Brett Lykins has pretty much answered your question but without mentioning any techniques specifically. If you wanted some further clarification then two main techniques very commonly ...
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  • 5,270
4 votes

Switch Buffer Sizing

First, there is a relationship between buffer size and latency only if there is congestion in the path (too many incoming packets on the input interface, or too many packets for the switching engine (...
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  • 2,396
4 votes
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Does the direction of a throughput bottleneck matter?

If a network has a throughput bottleneck, does it matter whether the slow link comes before or after? No it doesn't, Only matters when destination is before or after that bottleneck link. What ...
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4 votes

Speed benefits when switching from 1Gb copper LAN to Fiber Optic

Working with network shares, the #1 bottleneck is usually the server, not the network. For 20 users each simultaneously moving 400 Mbit/s, the server would have to cope with 8 Gbit/s which is quite a ...
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  • 69.7k
4 votes

Cisco 892 Low WAN Speeds

Slightly better than 350Mbit/s? That's probably about as good as it's going to get with an 890 series and with NAT. NAT is probably causing the CPU load, here. Don't forget: This product range is ...
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4 votes

Transferring data speed of Fast Ethernet

You'd be correct. However I'd say that what you're referring to as a packet should be considered a file. This is because the data of the file will be truncated (as you put it) into smaller bites of ...
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4 votes
Accepted

Bandwidth limit between CPE and Provider Equipment

There is no interface rate that runs at precisely 15 Mbit/s. The most common handover interface is Ethernet which exists for 10, 100, 1000 Mbit/s or faster. Your plan's data rate is implemented as ...
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  • 69.7k

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