Asterisk ss7 configuration

Configuration of chan_ss7


The Asterisk configuration file for chan_ss7 is called ss7.conf. It should be placed with the other Asterisk configuration files, ie. typically /etc/asterisk/. The description here is applicable for version 1.1.

The config file contains a number of sections: [linkset-name] sections where linksets are defined, [link-name] sections where links are defined(ie. circuits with SS7 CICs) are set up, [host-name] sections where hosts are defined, and finally a [cluster] section defining the cluster configuration.


Linkset section

hunting_policy. This sets the hunting policy, ie. the algorithm used to allocate a circuit for outgoing calls. This should be configured appropriately at each end of the SS7 link to minimize the risk of call collision (both ends try to make an outgoing call on the same circuit at the same time). Possible values are odd_lru (allocate odd CICs in preference to even CICs, and within each group pick the least recently used CIC); and even_mru (allocate even CICs in preference to odd CICs, and within each group pick the most recently used CIC). The default is odd_lru.
enable_st. This is used to decide whether end-of-pulsing (ST) is not used to determine when incoming address is complete.
use_connect. This settings specifies whether to eply incoming call with CON rather than ACM and ANM
context. The asterisk context to use for incoming calls on this linkset. Defaults to default.
language. The asterisk language to use for incoming calls on this linkset. Defaults to the empty string.
noa Nature of Address

Link section

linkset. The linkset that this link belongs to
channels.The speech/audio circuit channels on this link.
schannel. The signalling channel
firstcic. The first CIC on this link
rxgain. rxgain
txgain. txgain
auto_block. When set to yes, the CICs on that link are blocked when signalling on the link is lost.
echocancel can be one of: no, 31speech (enable only when transmission medium is 3.1Khz speech), allways
echocan_train specifies training period, between 10 to 100 msec
echocan_taps specifies number of taps, 32, 64, 128 or 256



Host section

chan_ss7 auto-configures by matching the machines host name with the host-<name>
section in the configuration file. The same configuration file can thus be used on several hosts.

default_linkset. This sets the SS7 linkset that receives outgoing calll where no linkset is defined in the Dial command'.
opc. The point code for this SS7 signalling point
dpc. A list of linkset:point-code pairs that specifies the point code to use for the linkset.
If the link connected to an STP (with point code 0x123), you may use
dpc => siuc:0x3ff,l1:0x123
links. A list of link:connector-no pains that specifies which links are on which connectors.

Jitter section

[jitter] 
jbenable = yes
jbmaxsize = 1000
jbresyncthreshold = 1000
jbimpl = adaptive


Cluster section


This section has an entry for each link that is monitored by another host. Each eantry has a list of host#address pairs.

All sections has an enabled entry; if this entry is no, chan_ss7 disregards the section.

The source code distribution of chan_ss7 comes with a number fo configuration templates.

Configuration of chan_ss7


The Asterisk configuration file for chan_ss7 is called ss7.conf. It should be placed with the other Asterisk configuration files, ie. typically /etc/asterisk/. The description here is applicable for version 1.1.

The config file contains a number of sections: [linkset-name] sections where linksets are defined, [link-name] sections where links are defined(ie. circuits with SS7 CICs) are set up, [host-name] sections where hosts are defined, and finally a [cluster] section defining the cluster configuration.


Linkset section

hunting_policy. This sets the hunting policy, ie. the algorithm used to allocate a circuit for outgoing calls. This should be configured appropriately at each end of the SS7 link to minimize the risk of call collision (both ends try to make an outgoing call on the same circuit at the same time). Possible values are odd_lru (allocate odd CICs in preference to even CICs, and within each group pick the least recently used CIC); and even_mru (allocate even CICs in preference to odd CICs, and within each group pick the most recently used CIC). The default is odd_lru.
enable_st. This is used to decide whether end-of-pulsing (ST) is not used to determine when incoming address is complete.
use_connect. This settings specifies whether to eply incoming call with CON rather than ACM and ANM
context. The asterisk context to use for incoming calls on this linkset. Defaults to default.
language. The asterisk language to use for incoming calls on this linkset. Defaults to the empty string.
noa Nature of Address

Link section

linkset. The linkset that this link belongs to
channels.The speech/audio circuit channels on this link.
schannel. The signalling channel
firstcic. The first CIC on this link
rxgain. rxgain
txgain. txgain
auto_block. When set to yes, the CICs on that link are blocked when signalling on the link is lost.
echocancel can be one of: no, 31speech (enable only when transmission medium is 3.1Khz speech), allways
echocan_train specifies training period, between 10 to 100 msec
echocan_taps specifies number of taps, 32, 64, 128 or 256



Host section

chan_ss7 auto-configures by matching the machines host name with the host-<name>
section in the configuration file. The same configuration file can thus be used on several hosts.

default_linkset. This sets the SS7 linkset that receives outgoing calll where no linkset is defined in the Dial command'.
opc. The point code for this SS7 signalling point
dpc. A list of linkset:point-code pairs that specifies the point code to use for the linkset.
If the link connected to an STP (with point code 0x123), you may use
dpc => siuc:0x3ff,l1:0x123
links. A list of link:connector-no pains that specifies which links are on which connectors.

Jitter section

[jitter] 
jbenable = yes
jbmaxsize = 1000
jbresyncthreshold = 1000
jbimpl = adaptive


Cluster section


This section has an entry for each link that is monitored by another host. Each eantry has a list of host#address pairs.

All sections has an enabled entry; if this entry is no, chan_ss7 disregards the section.

The source code distribution of chan_ss7 comes with a number fo configuration templates.
Created by: knielsen, Last modification: Mon 10 of May, 2010 (19:08 UTC) by cervajs
Please update this page with new information, just login and click on the "Edit" or "Discussion" tab. Get a free login here: Register Thanks! - Find us on Google+