|
|
 | Caution Beginning with Cisco IOS Releases 12.0(7)XK and 12.1(2)T, this feature is no longer supported. |
This chapter describes how to configure a Cisco MC3810 multiservice access concentrator for Voice over High-Level Data Link Control (VoHDLC), a protocol that provides Cisco serial encapsulation.
VoHDLC enables a Cisco MC3810 to carry live voice traffic (for example, telephone calls and faxes) back-to-back to a second Cisco MC3810. VoHDLC on the Cisco MC3810 is supported on serial ports 0 or 1, or on 0:x (the T1/E1 trunk, where x represents the channel group number).
This chapter is organized as follows:
Configuring VoHDLC is simpler than configuring VoFR or VoATM. Because the target voice-network peer is another Cisco MC3810 configured back-to-back with the first Cisco MC3810, you do not have to configure the network backbone to support VoHDLC.
Before you can configure HDLC dial peers, you need to configure the HDLC voice encapsulation.
To configure HDLC voice encapsulation, complete the following steps in global configuration mode:
| Step | Command | Purpose |
|---|---|---|
| 1 | router(config)# controller | If you will configure VoHDLC over the T1/E1 trunk, enter controller configuration mode. If you will configure VoHDLC over serial port 0 or 1, proceed to step 4. The number should be 1 if the controller is for the interface to the local phone device or PBX (through the DVM). The number should be 0 for the interface to the WAN (through the MFT). |
2 | router(config-controller)# tdm-group tdm-group-no timeslot timeslot-list | Configure a time-division multiplexing (TDM) channel group for the controller. |
3 | router(config)# interface serial 0:x point-to-point | If configuring VoHDLC over the T1/E1 trunk, enter interface configuration mode by specifying serial 0:x, where x is the channel group number. Note In Cisco IOS Release 11.3(1) MA, serial port 2 was a valid port number. Beginning with Release 12.0, serial 2 is not a valid designation on the Cisco MC3810.Proceed to step 6. |
| 4 | router(config)# interface serial number point-to-point | If configuring VoHDLC over a serial port, enter interface configuration mode and configure serial interface 0 or 1. |
| 5 | router(config-if)# voice-encap size |
Proceed to the next section, "Configuring Dial Peers."
Dial peers describe the entities to and/or from which a call is established. Dial-peer configuration tasks define the address or set of addresses serviced by that dial peer and the call parameters required to establish a call to and/or from that dial peer.
There are two different kinds of dial peers:
POTS dial peers associate a telephone number with a particular voice port so that incoming calls for that telephone number can be received and outgoing calls can be placed. HDLC peers point to specific voice-network devices so that incoming calls can be received and outgoing calls can be placed. Both POTS and HDLC dial peers are needed to establish VoHDLC connections if you want to both send and receive calls. Establishing two-way communication using VoHDLC requires establishing a specific voice connection between two defined endpoints.
The following sections describe how to configure POTS and VoHDLC dial peers.
Depending on your dial plan configuration, you may need to consider how to configure voice networks with variable-length dial plans, number expansion, excess digit playout, forward digits and default voice routes, or use hunt groups with dial-peer preferences. For more information on these topics, see "Voice Dial Plan Considerations."
To configure POTS dial peers, complete the following steps from global configuration mode:
| Step | Command | Purpose |
|---|---|---|
| 1 | router(config)# dial-peer voice tag pots | Define a POTS dial peer and enter dial-peer configuration mode. All subsequent commands that you enter in dial-peer voice mode before you exit will apply to this dial peer. The tag value identifies the dial peer and must be unique on the Cisco MC3810. Do not duplicate a specific tag number. |
| 2 | router(config-dialpeer)# destination-pattern string | Configure the dial peer's destination pattern. The string is a series of digits that specify the E.164 or private dialing plan telephone number. Valid entries are the digits 0-9 and the letters A-D. The following special characters can be entered in the string:
The plus symbol (+) is not a valid character in the string. |
| 3 | router(config-dialpeer)# port slot/port | Associate this POTS dial peer with a specific logical dial interface. Enter the slot/port number of the voice port connected to the POTS dial peer. |
| 4 | router(config-dialpeer)# forward-digits {num-digit | all | implicit} |
The default value is implicit, in which the exactly matched digits are not forwarded. Only digits matched by the wildcard pattern are forwarded. For more information about the forward-digits functionality, see the "Forward Digits and Voice Default Routes" section. |
| 5 | router(config-dialpeer)# prefix string |
To configure the next POTS dial peer, exit dial-peer configuration mode by entering exit, and repeat the previous steps. To configure the HDLC dial peer, see the next section.
Depending on your dial plan configuration, you may need to consider how to configure voice networks with variable-length dial plans, number expansion, excess digit playout, forward digits and default voice routes, or use hunt groups with dial-peer preferences. For more information on these topics, see "Voice Dial Plan Considerations."
To configure VoHDLC dial peers, complete the following steps from global configuration mode:
| Step | Command | Purpose |
|---|---|---|
| 1 | router(config)# dial-peer voice tag vohdlc |
The tag value identifies the dial peer and must be unique on the Cisco MC3810. Do not duplicate a specific tag number. |
| 2 | router(config-dialpeer)# destination-pattern string | |
| 3 | router(config-dialpeer)# session target interface serial-port-number | Configure the HDLC session target for the dial peer. For the serial-port-number value, enter either 0 and 1. |
| 4 | router(config-dialpeer)# preference value | (Optional) Configure a preference for the VoHDLC dial peer. The value is a number from 0-10 where the lower the number, the higher the preference. |
| 5 | router(config-dialpeer)# alt-dial string | (Optional) Configure the alternate dial-out string when configuring on-net-to-off-net alternative dialing. |
To configure the next HDLC dial peer, exit dial-peer configuration mode by entering exit, and repeat the previous steps.
If you have relatively few dial peers configured, you can use the show dial-peer voice command to verify the validity of your dial-peer configuration.
If you are having trouble connecting a call, you can try to resolve the problem by performing the following tasks:
Figure 8-1 shows an example of a simple back-to-back VoHDLC configuration.
interface Serial1 point-to-point ip address 5.5.5.1 255.0.0.0 no keepalive ipx network 2222 ipx accounting voice-encap 512 clockrate 64000 ip classless line con 0 exec-timeout 0 0 line aux 0 line vty 0 4 login voice-port 1/1 dial-peer voice 1 pots destination-pattern 3388801 port 1/1 dial-peer voice 2 pots destination-pattern 3388802 port 1/2
dial-peer voice 44 vohdlc destination-pattern 348.... session target Serial1 end
interface Serial1 point-to-point ip address 5.5.5.2 255.0.0.0 no keepalive ipx network 2222 ipx accounting voice-encap 512 clockrate 64000 ip classless line con 0 exec-timeout 0 0 line aux 0 line vty 0 4 login voice-port 1/1 dial-peer voice 1 pots destination-pattern 3488803 port 1/1 dial-peer voice 2 pots destination-pattern 3488804 port 1/2 dial-peer voice 40 vohdlc destination-pattern 338.... session target Serial1 end
Posted: Fri Jun 9 13:21:02 PDT 2000
Copyright 1989 - 2000©Cisco Systems Inc.