Pet Peeve on the networking forum...

Just a simple pet peeve... maybe some folks will gain a new respect for the usage of correct terminology haha

1. Frames ... When we refer to frames we refer to layer 2 of the OSI model.

2. Packets ... When we refer to packets we refer to to layer 3 of the OSI model.

examples...

Your dLink switch connects your PC (10.1.1.2/24) to your laser printer (10.1.1.3/24). They are on the same subnet and they are on a switch that can NOT do layer 3. The data sent back -n- forth is FRAMES.

Your dLink router connects your PC (10.1.1.2/24 to your Internet connection (externalIP/30). These connections are on two separate subnets. The frames from your PC are converted inside the router into PACKETS and sent to other routers as PACKETS where other routers then convert them to frames that other servers and PCs can read.

I see so many people derping the terms that are supposed to be professionals and it grinds my gears.

"I got this badass HP switch and it's not sending packets to my television sigh.. come on dawg what gives?"

or

"Our routers are having problems sending frames between our different VPN sites causing disconnects, any ideas?"

let us find humor in this as well

Speaking of nitpicking, what do you mean when you say data goes "through" the 3rd layer? L2 data includes the L3 data so how can it go "through" L3? Or "within, between, and across layer 3" for that matter? Data doesn't go "through" layers as if the layers are somehow planes that the data passes up and down inbetween. Data is classified as belonging to a certain layer based on what information it contains, with lower layers including all layers above.

From my experience, a "packet" is a defined amount of data. Wikipedia reflects this when it says "A data packet on an Ethernet link is called an Ethernet frame."

I would never call a TCP packet a frame, but you could call an Ethernet frame a packet.

TCM said:

Speaking of nitpicking, what do you mean when you say data goes "through" the 3rd layer? L2 data includes the L3 data so how can it go "through" L3? Or "within, between, and across layer 3" for that matter?

From my experience, a "packet" is a defined amount of data. Wikipedia reflects this when it says "A data packet on an Ethernet link is called an Ethernet frame."

I would never call a TCP packet a frame, but you could call an Ethernet frame a packet.

Click to expand...

Wiki did NOT define the definition.

Go look at Cisco or Juniper or Brocade and look at their documentation. That is all I am going to say.

Let me trim the fat down a little bit to make it easier to understand.

http://etherealmind.com/frames-packets-what-which-when/

A frame has a packet but a packet doesn't have a frame.

How about we go to TCP/IP Illustrated Vol. 1:

The unit of data that TCP sends to IP is called a TCP segment. The unit of data that IP sends to the network interface is called an IP datagram. The stream of bits that flows across the Ethernet is called a frame.

Click to expand...

"Packet" is just a general term for.. well.. packetized data. If you want to be 100% correct you say frame and datagram for L2 and L3, respectively.

This is where the "Lets have fun with this" kicks in haha.. I was hoping to get everyone involved to start a convo so people can learn from it in the long run.

TCM said:

How about we go to TCP/IP Illustrated Vol. 1:



"Packet" is just a general term for.. well.. packetized data. If you want to be 100% correct you say frame and datagram for L2 and L3, respectively.

Click to expand...

Actually a PDU / is a Cisco (typically) only term. So we might see that in the discussion as well.

What the big stink we are going to see is there is no absolute authority on the definition but we need to get the usage in scenarios correct.

Don't tell me, tell Stevens. I just quoted him.

And a short lesson about Token Ring:

Here's an easier way to look at it:

Frames carry Packets.
If there is a frame, there is a packet. The opposite is not always true, it depends on where exactly are you looking, and if MPLS is involved.

Also, routers still send out frames. Not to mention routers are starting to blur the line when you add MPLS into the mix, as you can have a packet within frame within a packet within a frame, repeating.

Pinski said:

Here's an easier way to look at it:

Frames carry Packets.
If there is a frame, there is a packet. The opposite is not always true, it depends on where exactly are you looking, and if MPLS is involved.

Also, routers still send out frames. Not to mention routers are starting to blur the line when you add MPLS into the mix, as you can have a packet within frame within a packet within a frame, repeating.

Click to expand...

I see yer keepin it [H] lol

quanta-
"My network is dropping quanta of data between my beer fridge and fish bowl, but seems to be fine between my router and the NSA."

tangoseal said:

Your dLink router connects your PC (10.1.1.2/24 to your Internet connection (externalIP/30). These connections are on two separate subnets. The frames from your PC are converted inside the router into PACKETS and sent to other routers as PACKETS where other routers then convert them to frames that other servers and PCs can read.

Click to expand...

Wrong. You need to brush up on your understanding of the OSI model. If it is on a wire it is a frame whether that framing be ethernet, token ring, frame relay, atm, the various T type framing or the various OC frame formats. Frames carry data not packets. The only place an OSI defined packet exists is the stack where it is being decoded and possibly re-encoded for retransmission. That stack can be inside a source, inside a router, inside a firewall, or inside destination. When an OSI packet is on the wire it is data inside a frame. It is *NEVER* a packet on the wire.

'frame' is probably the "most correct" usage of a term to describe the encapsulated data on the wire. as the data moves up the OSI layers 1 ~> 7 the previous headers may stay and have more encapsulation added to the "front" and "back" of the frame.

Haven't seen a "Which is the best anti-virus?" thread in a couple weeks. We're about due.

From what I understand, a router still sends frames but it just strips the src and dsty MAC addresses and re-encapsulates it into a frame with the appropriate technology (T1, ATM, etc) headers correct?

So the end result of this conversation is ....

NO ONE ON EARTH actually knows what a FRAME or PACKET is lol ....

My exact point was made... my pet peeve will never be sated because there is no one in the world who can truly define what they are.

If you ask me ... it's al 1's and 0's and the NSA is capturing it all as we speak muahaha