IP/VC 3510 MCU
The Cisco IP/VC 3520 Gateway can bond to a maximum of three ports for
calls that require transfer rates of up to 384 Kbps. Each BRI interface allows a
128 Kbps call. Units with four BRI interface ports can simultaneously support
four 128 Kbps calls, two 256 Kbps calls, or one 384 Kbps call and one 128 Kbps
call. Each V.35 port supports transfer rates from 56 Kbps to 768 Kbps.The V.35
ports either RS-366 or V.25bis signaling. Both the 3520 and 3525 have an
embedded gatekeeper, where each supports video formats of H.261 and H.263.
The main differences between the two models are their interface connections
and the scalability of calls.
The 3525 gateway supports ISDN PRI T1 and E1 connections.The IP/VC
3525 T1 model supports up to three videoconferencing calls at 384 Kbps, while
the 3525 E1 model supports five calls at 384 Kbps. If less quality is acceptable, 13
calls at 128 Kbps is supported. Keep in mind, the 3525 supports the same audio
transcoding formats as the 3520 (Figure 3.6).