Bohack » Telco

Cisco Console Cable Wiring

Bohack — Thu, 19 Nov 2009 15:13:59 +0000

Recently I needed to connect to a Cisco router and didn’t have a serial cable on hand. The Cisco routers just like their switches come supplied with a console port built in. This console port is usually a female RJ-45 in the back of the unit and is labeled console. A lot of other manufacturers also use this method to connect to their equipment; everything from Sun servers to appliance servers.

Usually I have a plenty of the cables on hand, but I could not find one of these in my box of tricks. I did have the EIA/TIA Serial to RJ-45 adapter, so I just needed the cable. The cable that comes supplied with Cisco equipment is a flat 8 wire telephone cable with two RJ-45 ends. The cable is called a rollover cable because Pin 1 is connected to Pin 8 on the other end and Pin 2 is connected to Pin 7 on the other end. It’ that simple!

It is sometimes called a null modem cable, because the all of the pins are reversed from side to side. The transmit is rolled over to the receive, the Ready To Send or RTS is directly connected to the Clear To Send or CTS, the Data Terminal Ready DTR is connected to the Data Set Ready or DSR, etc… All of the grounds are commonly tied together as well. This is why connecting to a Cisco device requires 9600 baud, 8 bits, No parity, 1 stop bit and no flow control. This is sometimes referred to as 9600,8,N,1.

The diagram below is how to make the rollover cable from simple Cat5 cable if you do not have the 8 wire flat Telco cable on hand that is usually gray in color. Simple crimp them down on each end of the cable as per the diagram. It does not matter which end is connected to the equipment and which end is connected to the EIA/TIA DB-9 RJ-45 connector.

T1 RJ-48C Wiring and the Smart Jack

Bohack — Sat, 16 May 2009 02:46:46 +0000

Again I find myself wiring up T1 circuits for a Telco provider that my company is going to use. I also find myself scouring the Internet for color codes for the T1 cable at the “Smart Jack”. The smart jack is where the demarcation point or demarc resides. So what is a demarc and what exactly is the smart jack… The demarc is where the Telco ends their responsibility and yours begins. The Telco needs a way to start your responsibility for wiring and internal maintenance, that is the threshold of the demarc. The smart-jack is a way that the phone company can loop or loopback the signal so that they can remotely check that everything is OK on their side.

Your interface with the smart jack is an RJ-48C connector, which is basically an RJ-45. When wiring the RJ-45 use the wiring spec of the TIA/EIA 568B color code. This color code is as follows…

However only Pin 1, Pin2, Pin 4 and Pin 5 are used… You only need to wire the 4 pins crimped to the RJ-45 connector. In the end the White/Blue and Blue pair of wires is your Transmit Ring and Tip and the White/Orange and Orange pair of wires is your Receive Ring and Tip. This basic wiring is what comprises a 4-wire T1 circuit with current Telco service today.

If you wanted to create a simple hardware loopback; you could simply connect Pin 1 to Pin 4 and connect Pin 2 to Pin 5. This would connect the Receive Ring with the Transmit Ring and connect the Receive Tip with the Transmit Tip. A connection like this would loop all data back to the Telco. You can fabricate a device like this with an RJ-45 connector and two wires. When you want to check your wiring you can; look at the smart jack (if you have access to it) and watch the ‘Alarm’ go off when you connect the loopback or call the Telco and have them verify the alarm is off. This is a simple way to check your T1 circuit all the way to your device.

How To Find Out Where Someone Lives by Their Phone Number

Bohack — Sat, 07 Feb 2009 19:02:30 +0000

Well you really can’t find out where someone lives exactly, only the phone company can tell you that and that information is confidential. However you can find which town someone lives in using the NPA/NXX database. The North America Numbering Plan was first introduced in 1947 and adopted by AT&T in 1951. The NANP was made to simplify and speed up long distance calls or calls that needed to leave the Central Office they originated from. That is where ‘Mabel’ would get on and you would ask to connect to Bayside-0213, Bayside was the central office or ’229′ b=2 a=2 y=9 or you could ask for 229-0123. The letters on the phone are there for a reason and that was when the NANP came into existence.

The NANP defined how areas would be numbered as well, areas being large area or Local Area Transport Areas (LATA). All calls in the area where charged at a predefined rate and in the 80′s that changed and where split into smaller area. However the Area Code or Numbering Plan Area are the same. So the Area Code / NPA for Pittsburgh is 412 this defines the Numbering Plan Area. Inside of the NPA there are several Exchanges or Numbering Plan Exchanges these are defined as NXX. This is the BAY/229 in Bayside. The last 4 digits of a phone number are the subscriber line and again that is private data.

So looking at a number like 412-229-0123 you can tell that it is in 412 or Pittsburgh. Inside of Pittsburgh the Exchange area or NXX is 229 or Bayside and the Subscriber is 0123. Well wouldn’t it be perfect if all exchanges matched like 229 is Bayside? Well 224 is also Bayside and that doesn’t work on a phone with the number encoding. Remember the NANP was introduced in 1947 and everyone owns a phone, so area were numbered outside of the first three letters encoded to the digits on a phone. You don’t call ‘Mabel’ anymore. There is a database published that Long Distance providers subscribe to for call routing. You can find pretty up to date version that are freely searchable on the Internet, just Google ‘npa nxx’ and you will find one. You can then locate a person down to the city they live in.