Analog VoIP Gateways
Gateway E&M FXO FXS DID/CLID
Catalyst 4000 Access Yes Yes Yes 12.1(5)T/12.1(5)T
Gateway Module
Catalyst 6000 Voice No No Yes No/Yes
T1/E1 Module
Cisco 1750 Yes Yes Yes Future
Cisco 2600 Yes Yes Yes 12.1(3)T/12.1(2)XH
Cisco 3600 Yes Yes Yes 12.1(3)T/12.1(2)XH
Cisco 3810 Yes Yes Yes 12.1(3)T/12.1(2)XH
Cisco AS5300 No No No N/A
Cisco 7200 No No No N/A
Cisco 7500 No No No N/A
Cisco DT-24+ and DE-30+ No No No N/A
Cisco VG-200 H.323v2 Yes Yes 12.1(5)XM1
If higher capacity voice channels are required to either the PSTN or PBX, a
digital gateway may be more effective.Table 3.3 lists the interfaces and features
supported on the various hardware platforms. The different gateways support two
main signaling types: either ISDN Primary Rate Interface (PRI) or channel associated
signaling (CAS) for T1 or E1. ISDN PRI, meanwhile, utilizes a “D”
channel for signaling. ISDN PRI is classified as out-of-band signaling since there
is a channel dedicated for signaling, whereas, CAS signaling (also referred to as
robbed-bit signaling) uses some of the bandwidth from each channel. CAS signaling
forms include loop start, ground start, and E&M.T1CAS supports automatic
number identifier (ANI) and dialed number identification service (DNIS)
as well, which are also known as Caller ID and Called Party Number. DNIS
returns to the called number they dialed. Determining which PRI type of interface
is required depends on whether you’re connecting your gateway to a PBX
or PSTN.Typically, if the gateway is connecting to a PBX, you will need a
Network Side PRI interface, since the PBX is on the “user side.” Normally, the
PSTN (with a switch like a DMS100) functions as the “network side” and the
gateway needs a User Side PRI interface.The gateway could be connected to
both the PSTN and PBX with ISDN PRI configured appropriately for each
interface.
www.syngress.com