Specifications

16 IBM Voice Over Frame Relay Perform Guide
IBM 9783 for digital lines such as T1,E1 for VoFR to VoIP migration point. See
4.2.4, “IBM 9783, 2212 at Headquarters and 2212 at Branch Offices” on page
105 for a detailed configuration.
2.7 2212 Network Design with Frame Relay
Figure 13. IBM 2212 with PBX versus IBM 2212 and IBM 9783
Figure 13 compares an IBM 2212 with a PBX against an IBM 2212 and IBM 9783.
From IBM 2212B Voice port to IBM 2212C Voice, port call routing can be done by
the PBX. But provided the communication between the 2212 A and PBX is analog
link and in this case 2 PBX E&M analog link is used one for transmitting the voice
traffic from 2212B to PBX through 2212A and one for transmitting the voice traffic
from PBX to 2212C through 2212 A. Encoding/decoding is done twice and
causes additional delay with poor voice quality. Because of 8 call processing rule
per voice port limitation, it is very difficult to design large networks that use a PBX
for call routing.
On the other hand, the IBM 2212 and IBM 9783 design does not require a PBX
for call routing. A PBX with a digital interface can also be connected to an IBM
9783. An IBM 9783 has a call routing function and it is used instead of a PBX. An
IBM 2212 and IBM 9783 are connected back-to-back using a frame relay
connection.
IBM
2212C
IBM
2212A
PBX
IBM
2212B
Frame Relay
PBX
IBM
IBMIBM
IBM
221X
Frame Relay
9783