Aastra Telecom 800 User Manual

PBX Networking

Technical Details

96

The automatic switching of call requests (i.e. routing) by means of bundle overflow 
or default numbering can lead to “circular switching”. 

To avoid this, a “transit” counter is incremented whenever a connection is 
switched through on Q.SIG lines. When the configured maximum value is reached, 
further switching stops.

A different PBX number must be set for each Aastra 800 in a PBX network. This 
setting can be found in the Web console, in the menu Telephony: Settings under 
the heading QSIG linking. You can also set the maximum value for the transit 
counter there. This value depends on the topology of the PBX network and should 
allow the system to have the maximum number of further connections possible.

You can display the connection status of the lines at any time in the Configurator 
menu System Info: Telephony: Trunks. You should check this in particular after 
making changes to a configuration to see whether all the lines used for system 
networking are operable.

Some of the features possible in Q.SIG are not supported by Aastra 800 with all 
their options, for example callback on busy within the Q.SIG network. The call cate-
gories defined in Q.SIG (e.g. Emergency Call, Operator, Normal) and the Q.SIG 
name transmission feature (“user names”) are fully supported.

The code digits to be used for seizing a route with open numbering are not trans-
mitted to the destination PBX and thus cannot be evaluated by it. To reseize a 
route (for example for a callback), you must set the appropriate digit prefixes in the 
bundle configuration for the routes to be reseized.

If, for example, you are configuring a route which can be 
seized using routing code “5” and have selected one or more 

PBX

200-299

PBX

500-599

PBX

300-399

PBX

100-199

PBX

400-499

D: a

4: b
D: c

3: e
5: h
D: d

3: i
D: g

5: k
D: f

a

b

c

d

e

f

g

h

i

k

D:Default
Route