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Zaptel.conf span syntax
Zaptel.conf span definition format
span definition format:
spannum= Number of the span. This begins at 1, and goes up one integer at a time. You may NOT have two spans with the same span number.
timing= How to synchronise the timing devices.
0: to not use this span as sync source; Send timing synchronisation to other end.
1: to use as primary sync source
2: to set as secondary and so forth
Use '1' if you want to use the circuit as your primary sync source. If '0' is used asterisk will try to provide timing to the span (say, if you were connecting to a legacy PBX). If Asterisk is connected directly to the telco you will want to use '1' to accept timing from them. If you have multiple spans, set them as 2, 3, 4, etc.
You must NOT use the numbers 1 and up more than once, for timing priority. Only 0 may be repeated, and 0 is usually only used if you are acting as network and not CPE.
Problems with timing manifest themselves different ways - with static, pops, and channels or calls regularly dropping.
LBO= Line Build Out - Length of cable between Zap card and SmartJack/telco provided modem. Almost always should be set to 0 unless you have a long cable. This distance does NOT include the copper in the street to the CO/exchange.
0: 0 dB (CSU) / 0 - 133 feet (DSX-1)
1: 133 - 266 feet (DSX-1)
2: 266 - 399 feet (DSX-1)
3: 399 - 533 feet (DSX-1)
4: 533 - 655 feet (DSX-1)
5: -7.5 dB (CSU)
6: -15 dB (CSU)
7: -22.5 dB (CSU)
Framing= how to communicate with the hardware at the other end of the line.
For T1: Framing is one of d4 or esf.
For E1: Framing in one of cas or ccs.
Coding= another parameter of the communication with the other end of line hardware.
For T1: coding is one of ami or b8zs
For E1: coding is one of ami or hdb3 (E1 may also need crc4)
In the examples below both spans will accept timing from the circuits they are connected to.
span=1,1,0,esf,b8zs - This is the FIRST digital Zaptel span on the system, has PRIMARY priority to receive timing FROM the other end of the link, the cable to the SmartJack/modem is less than 133 feet in length, this span uses ESF framing and B8ZS line encoding. A fairly typical T1 span definition.
span=2,2,0,ccs,hdb3,crc4 - This is the SECOND digital Zaptel span on the system, has SECONDARY priority to receive timing FROM the other end of the link, the cable to the SmartJack/modem is less than 133 feet in length, this span uses CCS framing and HDB3 line encoding, CRC4 error checking is also enabled. This is a fairly typical second E1 span definition.
span=3,0,0,esf,b8zs - This is the THIRD digital Zaptel span on the system. It SENDS timing to a device, such as a legacy PBX that's being piggybacked off the Asterisk system. This is a relatively unusual configuration, entered here for illustrative purposes.
- extract from Digium's Zaptel.conf: How to configure the low-level Zapata Interface Library for your hardware. http://www.digium.com/downloads/configuring_zaptel.pdf — vanished link
- alternate copy August 2007: http://www.surfcity.com/Asterisk/configuring_zaptel.pdf — 5 pg. document from 2002, nothing much not covered here already
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