Packet to bytes conversion

I am considering changing from a limitless ADSL connection to one where I am
charged by megabyte/gigabyte. The second option has a lower monthly fee. I
need to get an idea of my usage so I checked the connection (Network
Connections) used for the internet . (I use XP) The incoming and outgoing
traffic is displayed in packets and not bytes. Likewise, on the router where
traffic is also displayed in packets.

How can I convert the packets to bytes?

In article <c4gm61$st4$(E-Mail Removed)>, "Bobby"
(E-Mail Removed) says...
> I am considering changing from a limitless ADSL connection to one where I am
> charged by megabyte/gigabyte. The second option has a lower monthly fee. I
> need to get an idea of my usage so I checked the connection (Network
> Connections) used for the internet . (I use XP) The incoming and outgoing
> traffic is displayed in packets and not bytes. Likewise, on the router where
> traffic is also displayed in packets.
>
> How can I convert the packets to bytes?
>
You can't - packets are variable size. Run something like AnalogX
NetStat Live which will give you historic totals.

"Rob Morley" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) t...
> In article <c4gm61$st4$(E-Mail Removed)>, "Bobby"
> (E-Mail Removed) says...
> > I am considering changing from a limitless ADSL connection to one where
I am
> > charged by megabyte/gigabyte. The second option has a lower monthly fee.
I
> > need to get an idea of my usage so I checked the connection (Network
> > Connections) used for the internet . (I use XP) The incoming and
outgoing
> > traffic is displayed in packets and not bytes. Likewise, on the router
where
> > traffic is also displayed in packets.
> >
> > How can I convert the packets to bytes?
> >
> You can't - packets are variable size. Run something like AnalogX
> NetStat Live which will give you historic totals.

Ethernet packets are variable in size, but the maximum is around 1400 bytes
IIRC. When you are downloading files, I would expect that TCP/IP would use
the maximum packet size, so a conversion factor of around 1 packet = 1400
bytes is probably not going to be far wrong.

On 2004-04-01, Martin Underwood <(E-Mail Removed)> wrote:
> Ethernet packets are variable in size, but the maximum is around 1400 bytes
> IIRC. When you are downloading files, I would expect that TCP/IP would use
> the maximum packet size, so a conversion factor of around 1 packet = 1400
> bytes is probably not going to be far wrong.

This isn't a valid assumption, I'm afraid. The problem is that the maximum
packet size is just that, a maximum. When downloading a large file then the
majority of the packets will be that size, but otherwise the size will vary.
Things like responses to DNS requests will normally be quite small.

The MTU (Maximum Transmission Unit) can vary, but 1458 is normally the
recommended maximum for ADSL as supplied by BT, ethernet itself normally
uses an MTU of 1500.

Looking at the statistics from my firewall which records both packets and
bytes:

Ipkts Ierrs Ibytes Opkts Oerrs Obytes Coll
83355303 0 4289292222 63142178 0 2151902166 0

So, for packets inbound the average is about 51 bytes per packet, and for
outbound it's lower at about 34 bytes/packet. I don't do much downloading
(that is, no p2p etc.) but I do have some monitoring set up so I probably
average a smaller packet size than usual for a home user. Your figures would
probably be larger than mine, but you can't tell until you measure it. Lots
of downloading will tend to push you towards the maximum, but it's easy to
underestimate the amount of background noise that goes on :-)

Glyn.

Thanks Rob, Martin and Glyn.

Have now downloaded NetStat live.

"Glyn Grinstead" <*no-spam*@lusers.org> wrote in message
news:slrnc6qf0l.j72.*no-spam*@localhost.bimble.lusers.org...
> On 2004-04-01, Martin Underwood <(E-Mail Removed)> wrote:
> > Ethernet packets are variable in size, but the maximum is around 1400
bytes
> > IIRC. When you are downloading files, I would expect that TCP/IP would
use
> > the maximum packet size, so a conversion factor of around 1 packet =
1400
> > bytes is probably not going to be far wrong.
>
> This isn't a valid assumption, I'm afraid. The problem is that the maximum
> packet size is just that, a maximum. When downloading a large file then
the
> majority of the packets will be that size, but otherwise the size will
vary.
> Things like responses to DNS requests will normally be quite small.
>
> The MTU (Maximum Transmission Unit) can vary, but 1458 is normally the
> recommended maximum for ADSL as supplied by BT, ethernet itself normally
> uses an MTU of 1500.
>
> Looking at the statistics from my firewall which records both packets and
> bytes:
>
> Ipkts Ierrs Ibytes Opkts Oerrs Obytes Coll
> 83355303 0 4289292222 63142178 0 2151902166 0
>
> So, for packets inbound the average is about 51 bytes per packet, and for
> outbound it's lower at about 34 bytes/packet. I don't do much downloading
> (that is, no p2p etc.) but I do have some monitoring set up so I probably
> average a smaller packet size than usual for a home user. Your figures
would
> probably be larger than mine, but you can't tell until you measure it.
Lots
> of downloading will tend to push you towards the maximum, but it's easy to
> underestimate the amount of background noise that goes on :-)
>
> Glyn.