1) How will voice be entering the network? What device will be connecting to the Cisco Router?

Typical devices include:

PBX: Private Branch Exchange(PBX) is a phone switch. These can range in size from a few phones up to thousands of phones. If a customer is using advanced features (voice-mail, call hold, call waiting, three party calling, etc) then the customer probably has a PBX. Phones directly attach to a PBX and then the PBX would attach to a Cisco Router.

KeySystem: A KeySystem(KTS) can be generally described as a low-end PBX. It is a telephony device that allows the centralization of phone connections. A KeySystem handles basic call routing functions. Phones directly attach to a KTS and then the KTS would attach to a Cisco Router.

Phones:  Any analog phone can be connected to a Cisco Router provided the router is configured with ANALOG voice ports.

2) What interface type is on the customer's device?

Typical answers:

Analog ports: These ports support a single call per port.  There are several different types of analog ports including FXO,FXS, and E&M. See below for definitions.

Digital ports: This is typically a digital T1 and will support up to 24 calls per port.  However, it could also be an ISDN BRI or PRI.

3) How many calls does the customer want to support per site?

Definitions for the different Voice Interface Types:

For analog connections this is very important, because the analog ports only support one Voice Interface Type per port. For digital connections the same module can support all three Voice Interface Types.

FXS: Typically used to directly attach phones and fax machines.

FXO: Typically used to connect to the PSTN (local Telco), or to a PBX in rare instances.

E&M: Typically used to connect to a customer-owned PBX. 

***********************************************

2600, 3600 Voice Information

The Voice network modules work for both the 2600s and 3600s. There are two main pieces to configuring Voice for the 2600/3600. There is a voice network module and voice interface cards. The Voice network module has two options NM-1V (has 1 VIC slot) and NM-2V (has 2 VIC slots). The VICs are dependent on the interface type (FXO,FXS, and E&M). Each VIC has two ports of the same type: VIC-2FXS (2-port FXS), VIC-2FXO (2-port FXO), VIC-2E/M (2-port E&M).

The 3640 can support 3 voice network modules. So, if three NM-2Vs were used and two VICs were installed in each network module, the 3640 could support 12 analog voice ports.

The 2600s and 3620 can support 1 voice network module. So, if one NM-2V were used and populated with two VICs, these routers could support 4 analog voice ports.

Cisco 2600/3600 Voice Interfaces (required for Voice)

VoIP requires the PLUS Feature Set in either 11.3(7)NA or 12.0(2)XD.

VoFR requires the PLUS Feature Set in either 12.0(3)XG or 12.0(4)T.

***********************************************

AS5300 VoIP Information

The VoIP solution offered by the AS5300 is currently the only Digital Voice interface for doing VoIP.  So, if the customer has a Digital PBX and wants to connect it to an IP network, the AS5300 is the solution.  The Cisco AS5300 voice packet gateway solution includes the AS5300 Access Server, a voice/fax feature card, the voice gateway application software, which is integrated into Cisco IOS software, and the Cisco Voice Manager software application. 

The Cisco AS5300 voice/fax feature cards are coprocessor cards, each with a powerful RISC engine and dedicated high-performance Digital Signal Processors (DSPs) for each voice channel. There are two versions of the voice/fax feature card, one of which is a high-density model.  The original voice/fax feature card provides 24 digital voice connections for a T1 or 30 digital voice connections for an E1. The high-density model provides 48/60 digital voice connections.  Each AS5300 can accept two voice/fax feature cards, so the AS5300 can scale up to 96/120 voice connections within a single chassis.  Both voice/fax feature cards accept one to five DSP modules, each with either six or twelve voice DSPs.

Cisco AS5300 Voice Interfaces (required for Voice)

VoIP requires the PLUS Feature Set in either 11.3(7)NA or 12.0(3)T!!!

***********************************************

3810 Voice Information 

Cisco MC3800 Series Products

This is simply the chassis part number. The Chassis includes an ethernet port (RJ-45), 2 serial ports (DB-60), Console and Aux ports.

Cisco MC3800 Power Supplies (required)

Choose the desired power option. If the RPS option is ordered, the actual RPS power supply must be purchased separately (PWR600-AC-RPS).

Cisco MC3800 Voice Interfaces (required for Voice)

There are three options that are detailed below. A single 3810 CANNOT have more than one of these voice interface modules!

*1* If the customer requires a T1/E1/PRI digital voice interface, one of the following Digital Voice Modules must be selected.

*2* If the customer requires an ISDN BRI digital voice interface, the following BRI Voice Module must be selected.

*3* If the customer requires analog voice interfaces, the following Analog Voice Module must be selected.  This module does NOT provide any voice connectivity without first populating it with Analog Personality Modules.

**** For each analog voice port required, there MUST be an Analog Personality Module chosen from the list below. 

As stated above, one APM is required for every analog voice port needed. For example, if the customer requires 4 FXS ports and 2 E&M ports, the following modules would be ordered: MC3810-AVM6 (1-count), MC3810-APM-FXS (4-count), and MC3810-APM-EM (2-count).

Cisco M3800 Compression Modules (required for voice)

**** In order to determine the required compression modules, the number of voice calls supported and the type of compression being used is all that is needed.  These modules have either 3 or 6 DSPs each.  A DSP is a chip that performs voice compression.  Each MC3810 can hold a maximum of two Voice Compression Modules.

Number of Calls supported for each VCM combination:

DSP limitations are not a problem for the analog models.  This is because there are only 6 physical voice ports that may require compression.  A single VCM6 would allow the customer to compress these six calls using any available method.

The limited amount of DSPs may become a problem on the digital models.  With a digital interface, the maximum number of calls the MC3810 can support is 24. In order to compress 24 calls, G.729a compression MUST be used and the MC3810 must contain two VCM6s. However, if the customer only needs to support 12 simultaneous calls per MC3810, then G.729 compression could be used with the same hardware configuration.  This would yield slightly better voice quality.

Cisco MC3800 Multiflex Trunk Options (optional)

A MultiFlex Trunk (MFT) is not required to do VoFR on the MC3810, however, it is required to do VoATM.  The MFT is simply an enhanced T1/E1 interface with a built-in CSU/DSU.  Using the MFT for VoFR would keep the two serial ports available for other devices and would provide and end-to-end solution without the need for an external CSU/DSU.  The MFT may also be ordered with a BRI back-up interface.  The BRI interface type is S/T which requires an external NT-1 and is for DATA back-up only!!!   Consequently, only one of the MFT interfaces can be up at any given time, either the T1 port or the BRI port.

Cisco MC3800 Memory Options

**** See the IOS guidelines.

Cisco MC3800 Series Software Options

**** See the IOS guidelines.