Crossover firewire cable

[Ray]

There are two types of firewire cables: Straight-through and crossover.
Which one is the most common and what are they for? Your guidance is
appreciated.

Thanks,

Ray

 

[Rich Grise]

There are two types of firewire cables: Straight-through and crossover.
Which one is the most common and what are they for? Your guidance is
appreciated.

Even though there is only one type of connector used, there are two
kinds of ethernet ports - for lack of a better term, "client" and
"server". Your DSL modem has a "server" jack, as do routers, hubs,
and switches. Your built-in ethernet jack, and any add-on cards,
(except a "router" card) are "client" style. If you have two
computers _without_ any hubs, switches, or routers, and want
to connect their ordinary "client" style ethernet ports together,
you use a crossover cable, so that each "client" thinks the other
is a "server".

Hope This Helps!
Rich

 

[Impmon]

Even though there is only one type of connector used, there are two
kinds of ethernet ports

[snip]

And how this relates to Firewire? Just had to ask since the original
question is refering to Firewire cable and which type is more common.

 

[Rich Grise]

Even though there is only one type of connector used, there are two
kinds of ethernet ports

[snip]

And how this relates to Firewire? Just had to ask since the original
question is refering to Firewire cable and which type is more common.

OOps! OK, what's "firewire"? I'm guessing it's pretty much the same
deal with the cables, just from the context - there's a "straight-
through" and a "crossover" - it makes me think of the null modem
cables from days of yore.

OK, I've looked up "Firewire", and it uses hubs, so if they make
crossover cables, it must be to connect two devices without using
a hub. Call it a "null hub", maybe.

Thanks,
Rich

 

[Ray]

Rich,

I note that the external hard disk, dvd writer, etc., normally have two
firewire ports and requires a crossover cable to connect from pc to them and
some other device, i.e., iPod docking, that has one firewire port on it and
requires straight-through cable. When I buy the firewire cable, it seems
the shops do not know what type of cables they are selling, unlike CAT5
cable that normally marked on the packaging.

It leads me to find out if there are two types of cable readily available on
the market or iPod docking device accompanying cable is custom-made one. I
am unsure if the same technology of CAT5 cable is applied to firewire as
well. Your guidance is appreciated.

Thanks,

Ray

Even though there is only one type of connector used, there are two
kinds of ethernet ports

[snip]

And how this relates to Firewire? Just had to ask since the original
question is refering to Firewire cable and which type is more common.

OOps! OK, what's "firewire"? I'm guessing it's pretty much the same
deal with the cables, just from the context - there's a "straight-
through" and a "crossover" - it makes me think of the null modem
cables from days of yore.

OK, I've looked up "Firewire", and it uses hubs, so if they make
crossover cables, it must be to connect two devices without using
a hub. Call it a "null hub", maybe.

Thanks,
Rich

 

[Kitchen Man]

There are two types of firewire cables: Straight-through and crossover.
Which one is the most common and what are they for? Your guidance is
appreciated.

Interesting discussion. My browsing is showing that firewire cables
are not sold as "straight" and "crossover," but rather by connector
type. The 6-pin connector is the computer side, and the 4-pin
connector is the component side. So it would seem that if one wants
to connect PC to PC, you use a cable with two 6-pin connectors, and if
one wants to connect two peripherals together, one uses a 4-pin to
4-pin connector, etc.

Perhaps the people you are trying to buy cables from do not understand
what you want to buy because you are using the wrong terminology?

A little more digging reveals that IEEE-1394 uses a somewhat different
configuration than the Tx/Rx setup that those familiar with RS-232A
and ethernet would know, and is more akin to MIL-STD-1553. What has
driven you to believe that there are crossover IEEE-1394 cables? I'm
not saying there aren't, but I sure can't find any reference to them.
Are you using adapters that switch between 6-pin to 4-pin, or
male-to-female, that might be of non-standard construction?

http://www1.electusdistribution.com.au/images_uploaded/firewire.pdf
"NOTE that in all standard IEEE 1394 cables, the connections to the
two signal twisted pairs are transposed between the two ends. That is,
in a 6-pin to 6-pin cable pins 4 and 3 at each end connect to pins 6
and 5 at the other, respectively. Similarly in a 4-pin to 4-pin cable
pins 2 and 1 at each end connect to pins 4 and 3 at the other,
respectively."

 

[Ray]

Kitchen,

Many thanks for your good information.

You are quite right that most shops are selling 6-pin to 6-pin, 4-pin to
4-pin or 6-pin to 4-pin cable without mentioning crossover or
straight-through types. However, I do have purchased some cables that are
straight-through type and some docking devices that require such type of
cables.

One obvious different is that the devices that require straight-through
cable have only one firewire port while the devices that require crossover
or so-called standard cable have two firewire ports that can connect more
than one device in daisy-chain format. Does the connection method determine
the use of cable type?

Ray