Neuron: Missing Window in Windows 7

We've all run into that occasion where an application gets confused after going from dual monitors to one or some other change and ends up "invisible".  Usually it's somewhere very small or off on the screen that disappeared.  In Windows XP I would just right click on the program in the task bar and choose move and then use the arrow keys to move it to a visible location.  It's not quite that easy in Windows 7 since the option to move isn't there, but if you select the application and then type Alt+Space you will get the move menu.

Telephony Basics Pt 4

In previous posts I've explained terminology, color coding, and how to trace cables.  Now it's time to actually connect something.  As I showed in the first post of this series, there are two styles of punch down blocks for telephony, the 66 block and the 110 block.  These blocks are used to connect station cabling to the trunk cabling that goes from an IDF to the MDF.

Wires laid into the 66 block terminals.

Punch down and cut the wire.

Both styles of punch block use a punch down tool to terminate the wires to the block.  Many tools have a dual blade that can be flipped depending on which style of block is in use.  To terminate a wire, you place it into the terminal and then push it down to make contact with the punch down tool.  The punch down tool fits around a 66 block terminal or into a 110 block terminal.  One side of the blade is sharp to cut the wire off flush, this is normally marked on the tool with the word cut.  Be sure to have this side oriented to cut off the loose end of the wire and not the end going to the other block.

Laying out station cabling
in a 110 block.

Terminating a station cable onto 110.

110 5 pair tool

Terminating station cables to a 66 block or 110 block is similar to jumper cables except that you have 4 or more pairs instead of one.  The color code dictates that you should lay out your pairs white/blue, white/orange, white/green, white/brown, white/slate, red/blue, etc.  Each time you put a new station cable on it's white/blue pair would follow the previous cable's last pair.  These pairs are punched down on a 66 block into the outermost terminal.  On a 110 block, they are terminated by placing a plastic biscuit on top and punching it down on top of the wires.  Each biscuit terminates 5 pairs of wires at a time.  While you can use a standard 110 punch down tool, it is much easier to use a tool designed to punch five pair at a time like the one pictured.  Once the biscuit is in place, the jumper wires can be terminated one pair at a time.

In the same method, larger 25-pair cables can be terminated on a 110 or 66 block.  When doing larger cables, getting a neat appearance is often tricky until you have practice.  One phone technician told me to hide extra cable behind the block in case you ever have to reterminate a pair so that you don't have to reterminate the entire cable.  Below is a good howto video from YouTube on how to do 25-pair termination to a 66 block.

Telephony Basics Pt 3

One of the first things that I learned in my foray into the world of telephony was how to effectively use a cable toner.  Although I had used a toner before to trace network cabling, it was a different ball game using it with 66 and 110 blocks instead of modular patch panels.  For those who might not know, a cable toner consists of two parts, the tone generator and the probe.

Tone Generator

Probe

The probe detects the tone(signal) placed on the copper line and generates an audible sound.  The stronger the signal is, the louder the sound will be.  In telephony you usually plug the tone generator into a station cable that is in need of identification and then take the probe into the IDF.  When you get to the IDF, you can run the probe up and down the rows of the 66 blocks, but that method won't always get you the results you want.  An experienced telephone guy taught me to hold the probe in one hand near your ear (so you can hear it well) and then use a finger on your other hand to run down the conductors.  When you hear a tone, you can isolate it by using your finger to touch only one pair of conductors.  For example if the tone is coming on the blue/white cable pair you should be able to place your finger on the orange/white pair and not hear tone, but when on the blue/white you will hear tone.  There is only one drawback to the finger method... phones use voltage to ring which means that if you happen to hit a ringing line, it might bite a bit.

My particular model of toner is a Fluke Networks IntelliTone which has a digital tone option.  This comes in handy when there is digital phone signal or data signal on the line.  Using this option is the same as the analog method, but many times it will power through noise on the line.

Banjo

Another thing to keep in mind when toning out cables is how the color code corresponds with a modular jack.  Remember that most telephone cabling now uses the same color code as Ethernet.  Because of the switch to VoIP, cabling is often now run as all CAT5e or 6 and then used for voice.  When this is done and you plug in your tone generator, the tone will go on the blue/white pair (pins 4 and 5) since they are in the position for "line 1".  To split out the pairs you would have to have a "banjo" that has a modular jack on one end and conductors on the other corresponding to each pair.

Sometimes phone installers will split a CAT5e cable into two jacks with blue/white and orange/white on one jack, and green/white and brown/white on the other jack.  In this configuration green/white and  brown/white are wired to the blue/white and orange/white pins on the jack.

Telephony Basics Pt 2

Telephony is definitely not an area for the color blind.  Telephone cables and wires are all color coded to help with pair identification.

Mainly in older installations you will find the Bell Company solid color code which was as follows:

Pair One	Green	Red
Pair Two	Black	Yellow
Pair Three	White	Blue

This scheme did continue for larger numbers of pairs, but it is rare to see any cables with more than three pair left in service.

The modern scheme uses a repeated combination of a group color with a pair color.  The group and pair colors are:

Group	Pair
White	Blue
Red	Orange
Black	Green
Yellow	Brown
Violet	Slate

So using the group and pair colors, the first group of pairs will all have white matched with a color.  Usually the white wire has a tracer of the pair color to help with identification in case the cables become unwound.  Using these colors, you can uniquely identify 25 pairs.  Because the 25 pair cable and related termination on punch down blocks and other terminations is quite common, I have listed out the entire cable pair color chart below.

25 Pair Color Code from Wikipedia

Pair #	First wire	Second wire
1	White	Blue
2		Orange
3		Green
4		Brown
5		Slate
6	Red	Blue
7		Orange
8		Green
9		Brown
10		Slate
11	Black	Blue
12		Orange
13		Green
14		Brown
15		Slate
16	Yellow	Blue
17		Orange
18		Green
19		Brown
20		Slate
21	Violet	Blue
22		Orange
23		Green
24		Brown
25		Slate

Once you go past 25 pairs, the pattern repeats by using colored ribbons called binders to wrap each set of 25 pairs.  So the first set would be wrapped in white and blue ribbons, the next white and orange and so on.  

In networking, we've adopted the same color code for Ethernet cabling, but with only 4 pairs we only use part of the color scheme.  The Ethernet TIA586A and TIA586B standards define two different ways to terminate an Ethernet cable into a RJ-45 or an 8p8c connector.  Most use the B standard which places pair one (white/blue) in pins 4 and 5 which corresponds to line one in telephony.  Line two which is pins 3 and 6 is pair 3 (white/green).  TIA586A on the other hand puts pair 2(white/orange) in the pins 3 and 6.  This allows the termination to correspond to telephony line 2.  Mostly this is just knowledge to have for reference, but you may run across TIA586A in the wild.

Neuron: Cisco Switch Firmware Archive Command

First I should introduce this type of post.  For this blog, a neuron will be a short tidbit of information.

Anyone that has upgraded a Cisco switch in the last few years knows that they are usually distributed as a tar archive now.  To install the upgrade you do the following:

#archive download-sw tftp://tftpserver/upgradefile.tar

When you execute the command IOS downloads the file and extracts it onto the flash file system.  All you have to do after that is reboot.

Thanks to Cisco's latest grab for more money, if you don't have SmartNet on a piece of equipment, you can't download IOS code for it.  While this has long been their policy, it is now being enforced.  This isn't too much of a problem unless you have a device that dies and you want to replace it with a replacement that is also not under SmartNet.  The likelihood of the replacement switch coming in with the exact same IOS load is close to nil.  Most admins like to maintain certain revision levels on a certain model which poses the problem of how to get the IOS you want on the replacement.  Well the easiest way that I have found is to use Cisco's archive command again.  Keep in mind that it's best to do this BEFORE you have a switch crash.

#archive upload-sw tftp://tftpserver/firmwarefile.tar

When you execute this command, IOS will combine all of the files on the flash file system related to the IOS code into an tar archive and upload it to your TFTP server.  The resulting tar file can then be used like the stock Cisco firmware tar file.

Telephony Basics Part 1

My last post generated a lot of comments about what I would call traditional telephony or what VoIP (IPT) installers refer to as Analog, Public Telephone Switched Network (PTSN), or Plain Old Telephone System (POTS).  Three years ago I was handed a traditional PBX to manage with very little training or experience beyond Cisco Unified Call Manager.  To me at the time, the phone frame (equivalent to a patch panel in network parlance) looked like a tangled mess of spaghetti that I would never understand.  Thankfully I had a very patient manager and a local telephone consultant that helped me understand how things worked.

Terminology

66 Block

66 block: This is a type of punch down block used to terminate cabling.  The permanent wires are generally placed in the outer columns and the jumpers in the inner columns.  Some 66 blocks however have the permanent in the left most and up to three jumpers.

110 Block

110 block:  This is a type of punch down block used to terminate cabling. The permanent wires are terminated first and then a spacer block with conductors is placed on top where the jumpers are terminated.


Main Distribution Frame (MDF):  This is where the phone system's connections are terminated into either 110 or 66 punch down blocks.  Jumper cables are used to connect these terminations to house cabling, the telephone company demarcation point, or to other intermediary distribution frames.

Intermediate Distribution Frame (IDF):  This is generally a closet or enclosure in a remote part of the building that feeds back to the MDF via large 25 to 100 pair cables.  In the IDF jumpers are run from blocks connected to the feeder cables to blocks connected to house cabling.

Demarc (Demark, Demarcation Point):  This is the demarcation between what is the local telephone company's responsibility and what is the building owner's responsibility.  Usually this is an enclosure with some sort of terminating block inside of it.

Local Exchange Carrier (LEC):  This is the local telephone company that delivers the physical PTSN to the building demarc.  Alternatively in some areas there are Competitive LECs (CLEC) that provide services over the LEC's cabling.

Foreign eXchange Office (FXO):  This is the type of port that usually is connected to PTSN coming from the phone company.  It doesn't provide its own power or ground.

Foreign eXchange Station (FXS):  This type of port is generally found on PBXs and analog adapters for VoIP systems to "power" analog devices like fax machines and analog phones.  It provides ring and supervisory voltage to the line.

66 blade on left, 110 blade on right

Punch-Down Tool

Punch-Down Tool:  This is the device used to terminate a jumper or pair from a cable to a 66 or 110 block.  The tool generally can be used with different blades depending on the style of block you are using.

Spudger

Spudger (aka Spludger, Pick): This tool is used to remove or adjust jumper cables in cabling blocks.  It is very useful to pick out small bits of wire left behind after removing a termination.

66-Block Discovery

Today I got what is now a routine ticket for a MAC-D on a phone.  First a little background, unlike some of my luckier geek friends I don't administer a fancy Cisco Unified Call Manager or Avaya IP system.  My company's phone system is a Siemens/Rolm 9751 MOD 80 installed in 1996 and currently maintained by spare parts and good luck.  That being said, when a MAC-D comes in, it means working on the 66 Blocks in our MDF and IDFs to make the change instead of just having the user plug the phone into their new office's network jack and being done.

What was unique about today's ticket was that it introduced me to a new style of 66 block.  Usually 66 blocks have rows of 4 terminals with the two left ones having their opening facing to the center and the two right ones facing to the center like the picture shows below.

The block that the office I was working on was punched down onto though looked like this.

Notice how the three right most terminals face left and the 1 on the left faces right.  On a normal 66 block, the two terminals on the left are bridged and the two on the right are bridged so you would punch the riser cable to the outside terminal and the jumper to the inside terminal allowing each side to be independent.  On the block I found today it is actually setup to bridge all four terminals together.  You put the riser on the left most block and can put up to three jumpers onto the three right terminals.  From my research, it would seem this style of block was useful for shared lines.

I figured this might be of use to someone else that gets to deal with the inner workings of an old TDM phone system, even if it's just replacing it with something new.