Specifications

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Cisco Unity Express Voice-Mail and Auto-Attendant CLI Administrator Guide for 3.0 and Later Versions
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Chapter 23 Configuring Your Cisco IOS Gateway for T.37 On-Ramp and Off-Ramp Fax Support
Configuration Options
2. If the call is not detected as fax, a VoIP dial-peer is used (H.323 in case of Cisco Unified
Communications Manager and SIP in case of Cisco Unified CME) to route the call to the call agent.
(This is shown in
Figure 23-4 as steps 3 and 5 respectively.) The call agent routes the call to the
destination. (This is shown in Figure 23-4 as steps 6 and 8 respectively.) After the phone starts
ringing, the user picks up the phone or call is transferred to the voice mail on CFNA/CFB.
3. If the call is a fax call, irrespective of how Cisco Unity Express is integrated, the call is handed over
to outbound MMoIP dial peer. (This is shown in
Figure 23-4 as in as step 4.) The fax application
configured on the outbound MMoIP dial peer converts the fax into e-mail message with TIFF
attachment(s) and sends it to Cisco Unity Express. (This shown in
Figure 23-4 a as step 7.)
The user experience for this configuration can be described as follows:
1. A call is initiated.
2. The calling party starts hearing the ring tone, if the fax gateway is set up to play ring tone during
fax detection. Otherwise, calling party hears silence.
3. The called phone does not ring until the call is detected as a voice call and the gateway routes the
call to the phone.
4. If the call is detected as voice, the call is routed to the destination number using the SIP/H.323 dial
peer and the phone starts ringing. The call then proceeds like any other voice phone call.
5. If the gateway detects that the call is a fax, it is sent to a MMoIP dial peer and the fax is converted
into an e-mail message with a TIFF attachment. A fax then appears in the called party’s mailbox.
The calling party hears the CED tones and the fax is sent.
Using Listen First Mode with Separate DID
After you configure the dial peers for fax & voice calls, the calls can be routed to either a fax MMoIP
dial peer or a VoIP dial peer (for Cisco Unified CME, use SIP and for Cisco Unified
Communications Manager, use H.323). If customer has separate DIDs, we recommend that you use the
On-ramp application on the POTS dial peer (see the next section for more information about the
On-ramp application). However, you might want to use a mixed mode configuration, with some users
using a single DID for the fax and voice and other users using separate DIDs for fax and voice.
To configure fax detection application, see the “Configuring the Fax Gateway for the Fax Detection
Application” section on page 20.
Using the Fax Detection Application vs the On-ramp Application
You must use the fax detection application if you want to use the single DID functionality. However, the
fax detection application has limitations, as described in the “Using a Single DID for Voice and Fax”
section on page 5.
We recommend that you configure the On-ramp application, instead of the fax detect application, on the
fax gateway when you use separate DIDs for fax and voice calls. The sequence of events when you use
the On-ramp application, as shown in Figure 23-4, are:
1. The fax call is initiated from the fax machine. The fax machine establishes a POTS connection to
the Cisco IOS router POTS dial peer using an FXS or FXO port (shown in
Figure 23-4 as step 1).
The inbound POTS dial peer routes the call to the MMoIP dial-peer.
2. On the outbound MMoIP dial peer, the T.30 packets are converted into a fax e-mail message with a
TIFF attachment (shown in
Figure 23-4 as step 4).