RJ45 splitter for Ethernet - possible ?

Have a question or want to start a discussion? Post it! No Registration Necessary.  Now with pictures!

Threaded View
happen to run across this thread over on the Ethernet newsgroup -

Some guy found a RJ45 splitter (2-RJ45 jacks to 1-RJ45 jack)
over on ebay (search RJ45 spliiter) that look like the telco 1-line 2-line
adapters,
but yet this guy (and the ebay description) says these "splitters" ....

Features:
  a.. Convert a single RJ45 outlet to two RJ45 sockets easily, point for
more conveniently use

  b.. Increase the number of RJ45 network connections on an RJ45 outlet

  c.. Compact design, feel free to enjoy your internet surfing

  d.. Expand one RJ 45 outlet into two 8 wire RJ-45 T adapter, parallel
wiring

  e.. Connector: 3 x RJ45 female

  f.. 100% Brand New.

It doesn't even seem possible to have more "network connections"
by just splicing more Ethernet wires together vs a dumb hub ????

I could see if you were trying to split out the tip/ring (4/5) or power
(7/8)
but an Ethernet splitter ?????

--
----------------------------------
"If everything seems to be going well,
you have obviously overlooked something." - Steven Wright



Re: RJ45 splitter for Ethernet - possible ?

Quoted text here. Click to load it

The advertiser did not say "Ethernet network connections", he said
"network connections".  Telephone systems are called "networks", also.

However, his presumption that its compact size will somehow enhance your
internet experience is both stupid AND leads one to believe he thinks you
CAN tee an ethernet connection.

LLoyd

Re: RJ45 splitter for Ethernet - possible ?
I've had splitters like this in my tool box for the past decade, but
have not actually implemented them.

Mine, are male on one side, and two female on the other.

Imagine that you plugged one into a wall jack at the location of a
workstation, and another in the closet where your switch resides.

This would support two Ethernet or FastEthernet devices at the
workstation location (e.g.: host, and network attached printer).

Each device would utilize two of the four pairs within the 8-wire (e.g.:
Cat 5e) cable.

This is however, not an appropriate thing to do from a performance
standpoint, and should not be standard practice.

If you were utilizing GigEthernet, I believe all four pairs are used to
support a single device, and therefore splitting would not be an option.


Best Regards,
News Reader

P.Schuman wrote:
Quoted text here. Click to load it

Re: RJ45 splitter for Ethernet - possible ?
News Reader wrote:
Quoted text here. Click to load it

    ok - that pretty much answers the rest of your points

Quoted text here. Click to load it

    really - how ?

Quoted text here. Click to load it

    really - how ?
    considering that each Ethernet device normally expects pins 1/2 and 3/6
to be used ?
    So, you would have to fabricate a custom cable for each of these
connections at each end
    and then plug that cable into your cable-sharing RJ45 splitters..
    1/2 = 1/2
    3/6 = 3/4

    1/2 = 5/6
    3/6 = 7/8

Quoted text here. Click to load it



Re: RJ45 splitter for Ethernet - possible ?
P.Schuman wrote:
Quoted text here. Click to load it

You do not need to fabricate any custom cables, you just use a standard
straight through cable for each connection. The splitters are used in
pairs, one on each end of a single run of cable.
<http://www.homestead.co.uk/productcategorydetail.aspx?CategoryID=51338&onspecialoffer=False

Re: RJ45 splitter for Ethernet - possible ?
You are overlooking the key point.

The splitter is remapping pin placements.

Pins 1,2,3, and 6 on one of the female jacks are mapped to 1,2,3 and 6
on the male end, as you would expect.

The other female jack maps its pins 1,2,3, 6 to the other two wire pairs
(pins 4,5,7 and 8) on the male end.

Best Regards,
News Reader

P.Schuman wrote:
Quoted text here. Click to load it

Re: RJ45 splitter for Ethernet - possible ?
AH HAH -
YES.... IF the description mentions that the pins are re-mapped,
then we have a solution -
BUT only if deployed in pairs.
I used to use them for piggyback of Phone + Ethernet + IBM 3270
on a single 8-wire RJ45 jack installed to each cubicle.

The original thread was basically using ONE of these "splitters"
to just walk up to any RJ45 jack, plug in - and now have TWO jacks and TWO
computers connected.
OR - using a "splitter"  to run an Ethernet cable between several computers,
and basically T-connect them - as in the old coax days.

BTW - most of the eBay listings I clicked on made no mention of any
re-mapping,
so they might just be parallel RJ45's or ??  who knows what.

News Reader wrote:
Quoted text here. Click to load it



Re: RJ45 splitter for Ethernet - possible ?
The seller is not necessarily trying to deceive anyone.

Many products are promoted based on features, without any reference to
how to implement the functionality.

The eBay post was probably like most news posts, incomplete.

Best Regards,
News Reader

P.Schuman wrote:
Quoted text here. Click to load it

Re: RJ45 splitter for Ethernet - possible ?
Quoted text here. Click to load it

Yes, I remember a passive circuit for 10baseT that might
work under lucky conditions (short run, short patches).
No guarantees of any kind (including router port-burnout).
I doubt it would work at 100, and hubs are too cheap for
passive to be worth the risk.

-- Robert


Re: RJ45 splitter for Ethernet - possible ?
wrote:

Quoted text here. Click to load it

News has the right answer. These splitters break out the 4 pairs into
two sets of two. There is no problem with this in the ethernet
standard (cat 5 can support 2 ethernet lans if they are 10/100)
Don't do this with POTS phones unless you can live with the errors
when the phone rings.
It will not work with gigabit LAN, that needs all 4 pairs.

BTW I am doing this at my house and it works fine. (no packet errors)

Re: RJ45 splitter for Ethernet - possible ?
gfretwell@aol.com wrote:
Quoted text here. Click to load it

Since 10Base-T and 100Base-TX were both designed to coexist with phone
lines in the same cable, that shouldn't be a problem.

-Larry Jones

Start tying the sheets together.  We'll go out the window. -- Calvin

Re: RJ45 splitter for Ethernet - possible ?
On Fri, 28 Mar 2008 16:47:40 -0400, lawrence.jones@siemens.com wrote:

Quoted text here. Click to load it


Maybe BICSI has changed their opinion but that was what I heard when I
was in school. I know it works but it is not recomended

Re: RJ45 splitter for Ethernet - possible ?
Might want to check your system clock.

Your last post came in about an hour early.

:>)

Best Regards,
News Reader

gfretwell@aol.com wrote:
Quoted text here. Click to load it

Re: RJ45 splitter for Ethernet - possible ?
wrote:

Quoted text here. Click to load it

It says 2007 eastern

Re: RJ45 splitter for Ethernet - possible ?
The time indicated for your post (in the date column) says 9:08 PM,
which is offset an hour from the time you have indicated below (2007
hrs., i.e.: 8:07 PM).

Best Regards,
News Reader

gfretwell@aol.com wrote:
Quoted text here. Click to load it

Re: RJ45 splitter for Ethernet - possible ?
wrote:

Quoted text here. Click to load it

 I turned off the DST bit, see if that helps

Re: RJ45 splitter for Ethernet - possible ?
The time indicated for your post (in the date column) says 9:09 PM,
still an hour ahead.

Best Regards,
News Reader

gfretwell@aol.com wrote:
Quoted text here. Click to load it

Re: RJ45 splitter for Ethernet - possible ?
wrote:

Quoted text here. Click to load it

I'm baffled, I only know of one clock, the one in the lower right of
the screen. I don't know why it shows up as 909 in the header

Agent said 809 on the title bar when I looked at it

Re: RJ45 splitter for Ethernet - possible ?
gfretwell@aol.com wrote:
Quoted text here. Click to load it

No, it's not recommended (which I probably should have mentioned), but
it was designed to work.

-Larry Jones

It's going to be a long year. -- Calvin

Re: RJ45 splitter for Ethernet - possible ?
Possible and advisable are two different things.

A telephone ringing signal is an 88v 20Hz A.C. signal superimposed on
48v nominal D.C. supervisory voltage.

Hardly low voltage, and not appropriate for sharing a Cat 5e cable run
with data.

Readers should observe gfretwell's caution.

Best Regards,
News Reader

lawrence.jones@siemens.com wrote:
Quoted text here. Click to load it

Site Timeline