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Actual Packet : A PHY Layer question

Actual Packet : A PHY Layer question

Actual Packet : A PHY Layer question


a) My node generates a packet ( a PAM Signal in Ethernet , or 64-QAM in WiFi)
b) When the packet reaches the switch/access point and let us presume that the packet has to go to the (Public DNS)., what will happen to the original signal ( that is generated by my node (laptop) ) , i know for a fact that the signal will be restored and amplified at the switch (Ethernet) or Access point (Wi-Fi).
c) But during subsequent hops the signal is copied and restored, so it is no longer the signal that is generated by node,it is generated by the switching/routing device.

I just want a confirmation if the original signal from the node will be just copied into the a temporary cache and then the switch will generate its own reconstructed signal.

So in the circuit switched network there is just one signal from end to end, and that is the one that is generated by the Laptop, but in packet switched network, each of the signal is not the same in the sense each hop will generate the original signal , but the original signal from the laptop traverses up to the AP and the AP will take care of the functions of regenerating.

Bharat C P

RE: Actual Packet : A PHY Layer question

This link explains a little bit about Store and Forward, and why it's better.


The Ethernet switches in my house all mentioned Store and Forward.

RE: Actual Packet : A PHY Layer question

Also, even if it's not a Store and Forward Ethernet switch, the signal is still "reconstructed" at just about every step of the way anyway.

RE: Actual Packet : A PHY Layer question

Note that a carrier is free to modify or add packets to your message for its own purposes, and if the changes are removed prior to delivery to your destination, you would have some difficulty in discovering the carrier's surreptitious activity.

There has been some publicity recently about some carriers' practices; I thought that might answer the question you intended to ask.

Mike Halloran
Pembroke Pines, FL, USA

RE: Actual Packet : A PHY Layer question

Coming to think about it, yes the original signal has no meaning!!!!! I think weather digital or analog, once the signal is processed the original signal is no more, it is reconstructed, i guess, i would have to read of Reciever and circuit to really understand it. The question to start with was very generic but i had to ask , so every time the signal is received it is processed. Yeah, i need to understand about electronic devices and circuits to understand what happens, but coming to think about it the original signal has no meaning.

RE: Actual Packet : A PHY Layer question

" i need to understand about electronic devices and circuits to understand what happens, "

Not really, depending on your end purpose. If it's only to get a general idea of what happens, then treating circuits as black boxes that do nothing more than "reconstruction" is more than adequate. Unless you intend to design circuits, anything more in depth is unnecessary. There used to be a time when integrated circuits were relatively young that there were required course in college to learn circuit design, but not anymore, I think.

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