Specifications

IPmux-1/1E Installation and Operation Manual Chapter 1 Introduction
Functional Description 1-13
There are two modes of bundle redundancy:
• 1+1 – Both the primary and secondary bundles transmit TDMoIP® traffic, but
only the active bundle receives TDMoIP® traffic, while the redundant bundle
ignores the Rx path. This mode results in minimum recovery time between the
bundles whenever switch/flip occurs, but on the other hand increases the total
throughput.
• 1:1 – Only one bundle transmits and receives TDMoIP® traffic while the
secondary bundle is kept on hold. This mode does not affect the throughput,
however, it increases the recovery time of the system in case switch/flip occurs
(depends on the network elements involved in the application). In 1:1 mode,
the active and redundant paths are monitored continuously to detect failure
and initiate the flip/switch using OAM keep-alive messages.
The following figures illustrate typical bundle redundancy applications.
In Figure 1-11 IPmux-1 duplicates the incoming TDM traffic internally in order to
create a redundant bundle. Each bundle is routed to a different IP/Ethernet/MPLS
network.
Packet
Switched
Network
IPmux-1
Radio Link
E1/T1 E1/T1
PBX
Primary Active Bundle
Redundant Bundle
PBX
IPmux-1
Figure 1-11. Bundle Redundancy Application (A)
In Figure 1-12 two separate IPmux-1 units are fed with the same E1/T1 stream and
provide two bundles. The bundles are routed into two different paths. The remote
IPmux-1 is responsible for administering the primary and secondary bundle activities.
Packet
Switched
Network
IPmux-1
Satellite Link
E1/T1
E1/T1
E1/T1
PBX
Primary Active Bundle
Redundant Bundle
PBX
IPmux-1
IPmux-1
Figure 1-12. Bundle Redundancy Application (B)