Julian, Thanks for your comments. ----- Original Message ----- From: "Julian Lyndon-Smith" <[EMAIL PROTECTED]> To: "Discussions regarding The Asterisk Documentation Project" <asterisk-doc@lists.digium.com> Sent: Thursday, August 11, 2005 3:25 PM Subject: Re: [Asterisk-doc] Connecting to a PRI
> Comments inline: > > Many thanks for taking the time to doc this. > > Julian. > > Gene Naden wrote: > > Here is my explanation of the issues involved in connecting to a PRI. I am > > open to feedback, corrections, comments. This is a text file with line > > breaks. > > > > Gene Naden, MA > > Programmer Analyst > > GlobalTeldata II, LLC > > 4700 N. Ravenswood > > Chicago, IL 60640 > > (773) 878-3161 x 223 > > > > > > ------------------------------------------------------------------------ > > > > WHAT IS A PRI? > > > > A PRI is a 24-channel connection to a telephone network such as the Public > > Switched Telephone Network (PSTN). PRI is a type of ISDN (Integrated > > Services Digital Network) connection. A PRI can carry 23 voice channels. > > The 24-th channel is used for signalling. The voice channels are referred > > to as B channels and the signalling channel is referred to as the D channel. > > Euro ISDN PRI have 31 channels, 16th used for signalling > > > > > Because a PRI uses a four-wire local loop, d4 or esf framing, and AMI or B8ZS > > coding, it may also be referred to at T-1. However, T-1 can be used to carry > > either voice or digital data. > > or E1 for euroisdn > > > > > You specify the type of framing and coding when you provision the PRI with the > > telephone company. > > > > CONNECTING TO A PRI > > > > To connect to a PRI you use Zapata technology. Zapata is also used for > > connecting to POTS lines (ordinary, single channel analog phone lines) and > > analog phones. You configure Zapata for Asterisk in the file /etc/zaptel.conf. > > Therefore this file can have information about both PRI connections and POTS > > line connections. See the example below. > > > > You do not need a Channel Service Unit/Data Service Unit (CSU/DSU) to connect > > your PRI to the Asterisk computer. > > > > The Digium cards for PRIs accept RJ45 plugs, the same type of plug used > > in Category 5 cables. > > > > All the Digium cards for connecting to a PRI are PCI cards. Therefore, you > > cannot use a 1U rack-mounted server if you are connecting to a PRI. The TE405P > > Um, we are - most 1U servers have riser boards allowing for the card to > be mounted sideways. Both our TE405p and TE405P are in 1U servers. > > > card is an example of a PRI interface card. It has four ports and therefore > > can connect to up to four PRIs. Alternatively, one or more ports could be > > connected to channel banks for analog phones. However, channel banks are > > beyond the scope of this discussion. > > > > Below is a sample Zapata configuraion file (zaptel.conf). It shows the > > configuration for a single PRI, two analog phones and two POTS lines. > > > > # zaptel.conf > > > > loadzone = us > > > > #te405p card > > span=1,1,0,esf,b8zs > > bchan=1-23 > > dchan=24 > > fxols=1-23 > > > > > #tdm400 card > > fxoks=97-98 > > fxsks=99-100 > > > > The 23 B channels and the D channel are shown. > > > > The line "fxols=1-23" reflects the fact that the connection is to a PRI > > rather than a channel bank. "ls" refers to "loop start." > > > > The way the channel numbering works is that the first 96 channels (one > > through 96) are for the TE405P card. The fxo and fxs channels, if any, > > must follow, rather than precede, the PRI channels. In other words, > > you cannot have fxoks=1-2, fxsks=3-4, bchan=5-27, dchan=28. If you > > do this you will get an obscure error message. > > > > Regarding the line beginning with the word "span", there is one span > > for each port that is in use. The "span" line has the following format: > > > > span=port number, timing, line build out, framing, coding > > > > The port number is one because the PRI is connected to the first port on the > > card. > > > > The timing should be 1 for one of the ports. The line connected to that > > port provides a timing reference. If other ports are used, the timing for those > > ports should be two or zero. Two means this line is a secondary timing reference > > and zero means this line is not used as a timing reference. > > > > Line build out reflects the length of last leg of the connection and is set to > > zero if the length is less than 133 feet. The specific values for line build > > out are specified in the sample zaptel.conf that comes with Asterisk. > > > > The framing and coding are discussed in "WHAT IS A PRI", above. The option "esf" > > refers to "extended super frame" and "b8zs" refers to "Bipolar with 8 Zero > > Substitution." > > > > TROUBLE-SHOOTING > > When the PRI card was purchased from Digium, Digium has provided free > > technical support for configuring the card. > > > > The lights on the PRI card can be red, amber/green or green. When all is > > well they are green. > > > > If Asterisk aborts when you try to start it, there are several things you > > can check: > > > > The Linux modules for your Zapata cards have to be loaded in order for the > > connections to work. You load the PRI driver, wct4xxp, before you load the > > FXS/FXO driver, wctdm. > > > > You also have to execute the program ztcfg to get things to work. If all is > > well, when you run ztcfg it should not produce any output. When you > > do this, the lights should change to green, even if Asterisk has not been > > started. > > > > Loading of the modules may or may not be done automatically by the system. > > > > It is possible to construct a loop-back plug to test your PRI card. > > You do this using an RJ45 plug, connecting pin one to pin four and pin > > two to pin five. When the loop-back connector is connected to the card, the > > light should turn green. Again, the modules have to be loaded and possibly > > ztcfg has to have been run. > > > > The B channels listed in zaptel.conf must agree with the channels listed in > > /etc/asterisk/zapata.conf, otherwise Asterisk may abort when you try to > > start it. > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > Asterisk-Doc mailing list > > Asterisk-Doc@lists.digium.com > > http://lists.digium.com/mailman/listinfo/asterisk-doc > > _______________________________________________ > Asterisk-Doc mailing list > Asterisk-Doc@lists.digium.com > http://lists.digium.com/mailman/listinfo/asterisk-doc > _______________________________________________ Asterisk-Doc mailing list Asterisk-Doc@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-doc