PSTN Punch Plan Requirements
A PSTN punch plan has three key requirements:
■ Entering alarm routing: Admission calls from the PSTN charge to be baffled accurately to
their final destination, which ability be a anon absorbed phone, including endpoints
that are handled by Cisco Unified Communications Manager or Cisco Unified
Communications Manager Express. This entering alarm acquisition additionally includes digit
manipulation to ensure that the admission Dialed Cardinal Identification Service
(DNIS), that is, the admission alleged number, matches the arrangement accepted by the
final destination.
■ Outbound alarm routing: Outgoing calls to the PSTN charge to be baffled to the voice
interfaces of the gateway—for example, a T1/E1 or a Foreign Exchange Office
(FXO) connection. As with entering calls, outbound calls ability additionally crave digit
manipulation to adapt the DNIS according to the PSTN requirements. This outbound
call acquisition usually includes stripping of any PSTN admission cipher that ability be
included in the aboriginal alleged number.
■ Actual PSTN Automatic Cardinal Identification (ANI) presentation: An oftenneglected
aspect is the actual ANI presentation for both entering and outbound
PSTN calls. The ANI for entering PSTN calls is generally larboard untouched, which might
have a abrogating appulse on the end user’s experience. The calling cardinal that is presented
to the end user should accommodate the PSTN admission cipher and any added identifiers
required by the PSTN to auspiciously abode a alarm application that ANI—for example,
using the absent calls directory.
Inbound PSTN Alarm Example
Figure 6-4 shows a alarm breeze for an entering call.
Chapter 6: Identifying Punch Plan Characteristics 329
User Dials
14085552001
PSTN
Call Bureaucracy From
PSTN:
DNIS 4085552001
Phone1-1
2001
Phone1-2
2002
UCME Gateway
DID 4085552XXX
15125556001
Gateway Modifies
DNIS to 2001 and
Routes to Articulation Port
1
2
3
V
Phone1-1 Rings
4
Figure 6-4 Entering PSTN Calls
A armpit consists of an H.323 aperture that is controlled by Cisco Unified Communications
Manager. The DID ambit of the PSTN block is 4085552XXX, and phones use the extension
range 2XXX. Here is the action the entering alarm goes through:
1. A PSTN user places a alarm to 14085552001; that is, to Phone1-1.
2. The alarm bureaucracy is accustomed by the aperture with a DNIS of 4085552001.
3. The aperture modifies the DNIS to 2001, the addendum of Phone1-1, and routes the
call to the articulation anchorage created back the IP buzz registered with UCME.
4. The buzz rings.
Outbound PSTN Alarm Example
Figure 6-5 shows a alarm breeze for an outbound call.
A armpit consists of an H.323 aperture and a Cisco Unified Communications Manager server.
The DNIS that Cisco Unified Communications Manager sends to the aperture includes
the PSTN admission cipher 9, and the ANI is the 4-digit addendum of the phone. The process
of the outbound alarm is as follows:
1. Application Phone1-1 with the addendum 0151, a user places a alarm to 9 
1 512 555-0101
.
2. The aperture accepts the alarm and modifies the DNIS to 1 512 555-0101, stripping
off PSTN admission cipher 9. The aperture additionally modifies the ANI to 408 555-0151 by
prefixing the breadth cipher and bounded cipher to the 4-digit extension.
H.323 Alarm Setup:
DNIS 915125550101
ANI 0151
Gateway Modifies
DNIS and ANI
User Dials
915125550101
5125550101
Phone1-1
0151
Phone1-2
0152
UCME Gateway
DID: 408555XXXX
Q.931 Alarm Setup:
DNIS 15125550101
ANI 4085550151
PSTN Phone
Rings
Figure 6-5 Outbound PSTN Calls
3. The aperture sends out a Q.931 bureaucracy bulletin to the PSTN with an ANI of
4085550151.
4. The PSTN subscriber blast at 512 555-0101 rings.