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45

These terms are abstract logical concepts, much like the OSI model. Data plane refers to all the functions and processes that forward packets/frames from one interface to another. Control plane refers to all the functions and processes that determine which path to use. Routing protocols (such as OSPF, ISIS, EIGRP, etc...), spanning tree, LDP, etc are ...


24

Forwarding Plane - Moves packets from input to output Control Plane - Determines how packets should be forwarded Management Plane - Methods of configuring the control plane (CLI, SNMP, etc.) Undestand the difference between Forwarding, Control and Management Plane


6

Electrical signals basically move at the speed of light in that particular medium. In (copper) wires that is usually around 70% - 90% of the speed of ligth (in a vacuum) or around 200,000km/s - 250,000km/s as opposed to the around 300,000km/s which light travels in vacuum. [Velocity Factor] Even the speed of light is not constant as is often referenced. The ...


6

First a word about: I understand word persistent as following : no one else can occupy wire at the time of persistent connection. So this connection is only one-to-one. But this is not right. Persistent connection can be established while other packets are going through the same wire. This is circuit-switched network vs packet-switching network ...


6

Humans do absorb RF, but the amount of attenuation caused by human bodies is less at lower frequencies. According to an abstract for a journal article, at 85 MHz: ...the local specific absorption rate (SAR) was found to be approximately equal to 0.05 W/kg... According to Wikipedia, LoRa uses the following frequency bands: ...169 MHz, 433 MHz, 868 MHz (...


5

1 --- Data Plane: These are software or hardware components of the router or switch related to routing/forwarding user data/traffic from one interface to another. In the case of routers, routing table and/or forwarding table (CEF in case of Cisco) and the routing logic constitute the data plane function. MAC Address Table and Switching logic comprise the ...


5

Data is binary-ones and zeros. Wireshark displays the data as hex characters so it’s easy to read.


5

SONET is a physical layer protocol (layer-1). You need a datalink layer protocol (layer-2) to handle framing. That was originally ATM, because that was one of the dominant L2's used by carrier networks. (vs. frame relay, ATM easily mixes voice and data.) IP (layer-3) "directly" over SONET still needs framing. Packet-over-SONET (POS) uses PPP (...


4

Ethernet layer 2 doesn't correct errors, it only detects them by frame check sequence (FCS). The algorithm for FCS is CRC with the polynomial G(x) = x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1. CRC cannot detect certain paired (even-number) bit error combinations - with a stable connection, these are very rare. A flaky ...


4

With gigabit endpoints (1000BASE-T) your injector needs to be gigabit capable as well. Cheap injectors insert power on the pairs unused by 10BASE-T and 100BASE-TX while disrupting the data transmission on these pairs. This only works when one of the endpoints falls back to 100BASE-TX - while this is quite common it's not to be taken for granted. The ...


4

If you look at the network layers, each layer of the network stack has a payload: Layer-2 frames have a payload of layer-3 packets. Layer-3 packets have a payload of layer-4 segments. Layer-4 segments have a payload of application data. Application data can also have its own datagrams, which have payloads, but anything above OSI layer-4 is off-topic here. ...


4

If all your connections between switches are layer 2, then yes, you need to trunk all VLANs across your backbone switch. The ports connecting your switches to the backbone will be configured as trunks, and you will tag VLANs. The ports connected to single devices (phones or PCs) will be untagged on the appropriate VLAN. If you have phones and PCs ...


4

You're close. The receiver ACKs a segment as long as there's still space in the receive buffer. When the upper layer (=application) doesn't read the buffer or is slow doing so, the free buffer space runs out and the receive window is reduced to avoid a buffer overrun. Simply ACKing on each receive would make the sender send more data - unless the upper layer ...


4

For routing protocols, “cost” might be better called “preference.” Presumably you would prefer higher bandwidth links, so they have lower cost.


4

As @teunvink says, check your logs. You can also check the SFP+ with this command: show interface te x/y/z transceiver detail and show interface te x/y/z transceiver properties


3

... and from the analogy department: You drive with an envelope containing a document which is a cover letter with a cheque which you're going to hand to someone. The car thinks you are the payload You think the envelope is the payload The envelope thinks the letter is the payload The letter thinks the cheque is the payload Correspondingly It is no ...


3

The IP fragmentation and reassembly is described by the RFCs. You must fragment on 64-bit boundaries. There are RFCs dealing with this, and other sites which will describe the fragmentation and reassembly process in depth; you can do a search to find them Start with RFC 791, INTERNET PROTOCOL: To fragment a long internet datagram, an internet protocol ...


3

Hi think you should have a look to https://scapy.net/, with not too much programming you can achieve the task of extract the packets and parsing as json, cvs or whatever.


3

It depends which MTU you are actually talking about: If you are talking about the layer-2 MTU, the IP packets are fragmented: Let's say you want to send an UDP packet with 5000 bytes length over Ethernet. In this case one IP packet is generated that is 5068 bytes long. This packet is then split into fragments of 1500 bytes length. The fragments are ...


3

The fundamental thing to understand is the separation of layers: don't try to understand all the layers at the same time. And probably best not to start with complex ones like HTTPS. Also it's vital to remember that the OSI seven layer model is just a story to help explain similarities and differences of networking processes; it is not followed by the ...


3

First things first: The TCP/IP suite of protocols was NOT based on the OSI model. Therefore, it is useless to attempt to describe them using that model. The TCP/IP model is much closer, but even so, models are abstract representations of functions, and they don't always match what is actually used. You have many questions to answer, but let me make some ...


3

In routing, cost is a measure for how much effort it takes to process and forward a packet or stream over a link or a path. As Ron has pointed out, this pretty much corresponds to the time the data occupies a link, therefore a higher data rate means less cost. (The worth may be the direct opposite. ;-) Depending on the perspective, metric may also be ...


3

This is the same term used in two different contexts and it has quite different meanings. (it could also have other different meanings in other domains) In the context of radio frequency, yes it is literally a range of frequency. For example WiFi 802.11 (legacy/b/g) use the 2.4 - 2.5 Ghz range and so has a 0.1Ghz bandwidth. In the context of network it ...


3

You cannot change IPv4's minimum MTU requirement because changing a fundamental requirement will break the Internet. Specifications exist so that any device design can be fully functional in any network. Imagine an industrial network where one components breaks or needs to be upgraded. The new component's changed specifications don't comply with the rest of ...


3

i completely understand that why receiver there is 576 bytes but my question is as technology update every after one Minutes then why we can't update that limit You fundamentally underestimate how hard it is to make a backwards-incompatible change to the Internet. If you make a backwards-incompatible change to the Internet, EVERY SINGLE DEVICE ON THE ...


2

In the modern state of networks and from a wide-area networking perspective, circuit switched links are basically merely last mile circuits. Such links are often categorized as analog or digital, such as T1's, PRI's, or telephone lines (sometimes called 1FB's by business customers). The reality is once the traffic is onto the carriers network, it's all ...


2

Such problem couldn't happen with circuit switching because, in circuit switching, a route and bandwidth is reserved from source to destination. Sometimes circuit switching can be relatively inefficient because capacity is guaranteed on connections which are set up but are not in continuous use, but rather momentarily. However, the connection is immediately ...


2

What is the actual function of the DCE ? , that is to provide clock rate to the DTE on the SERIAL link . This type of communications between two routers called (back to back routers connection) and could be between router on your site (your ownership) and other in ISP ownership, So answer of your questions is YES, DCE is responsible on the data transferee ...


2

From the Cisco NX-OS 5.1(3)N1(1) release and later releases, each Cisco Nexus 5500 Series device can manage and support up to 24 FEXs without Layer 3. With Layer 3, the number of FEXs supported per Cisco Nexus 5500 Series device is 8. With Enhanced vPC and a dual-homed FEX topology each FEX is managed by both Cisco Nexus 5000 Series devices. As a result, one ...


2

You need to read the fine print in the Cisco documentation: Maximum Limits—Indicates the maximum scale capability tested for the corresponding feature individually. This number is the absolute maximum currently supported by Cisco NX-OS Release 5.0(3)N1(1b) software for the corresponding feature. If the hardware is capable of a higher scale, future ...


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