Recent Changes - Search:

IP PBX Systems


VoIP Access Gateway


Download Center

Dealer Portal

Main Domain

Contact Details



Power Redundancy

By default, the Stillink 3200 has a single solid state, high quality, robust (with high MTBF value), convectional cooling (without mechanical fans), field-proven power system. Hallmarks of this power system are:

  • Built-in active PFC function
  • Short circuit / Overload / Over voltage protections
  • Cooling by free air convection
  • 100% full load burn-in tested
  • Fixed switching frequency at PFC:67KHz PWM:134KHz
  • Overload protection: Constant current limiting, recovers automatically after fault condition is removed
  • Overvoltage protection: Shut down o/p voltage, re-power on to recover
  • MTBF 224300 hours MIL-HDBK -217F (25 )

System Resources Redundancy

Although some of the Stillink 3200`s common control function is implemented in a centralized manner, many resources like digital signal processors (DSPs) are distributed. Digital signal processors provide HDLC, tone generators and register signals for E1 interfaces, as well as IP core protocols and codecs for VoIP calls. DSP distribution provides redundancy. When the capacity of the Stillink 3200 increases, number of DSPs increases too.

The SDT module in a Stillink 3200 has two high speed digital signal processors, each with 60 channels for various purposes as mentioned above. All available channels from all DSPs are collected in a common pool, which is ready to serve any request within the system. In other words, in case of a failure in a DSP, its functions can be handled with other DSPs in this distributed system. The expense in this method may be the traffic or concurrent call capacity.

TDM E1 Interfaces Redundancy

Stillink 3200 is a modular system with a capacity of 4 E1s to 32 E1s. Each SDT module in a Stillink 3200 has four E1 interfaces.

External synchronization sourcing is programmable and multiple E1 interfaces may be candidates for sourcing. Intelligent algorithms within the Stillink 3200 select the source among the available E1 interfaces. Consequently, loss of signal in an E1 interface does not necessarily cause the loss of synchronization.

The Stillink 3200`s alternate routing capability distributes outgoing call traffic over a number of routes leading to the same destination in case an E1 interface fails.

The Stillink 3200 continuously monitors E1 interfaces to determine any layer-1, 2, and 3 faults and warnings. Information gathered from this monitoring is used automatically for synchronization and route distribution.

IP Ethernet Interfaces Redundancy

The Stillink 3200 has multiple ethernet interfaces for IP Telephony. When the capacity of a Stillink 3200 increases, the number of ethernet interfaces increases too. Each SDT module in a Stillink 3200 has two ethernet interfaces. Each ethernet interface is capable of providing up to 60 concurrent VoIP calls.

The Stillink 3200`s packet switching capability resembles to its circuit switching capability. The Stillink 3200 continuously monitors ethernet interfaces for faults and warnings. Information gathered from this monitoring is used automatically by the system for VoIP calls route distribution.

E1 Protocol Level Redundancy

Some protocol types have inherently redundancy to protect calls. To illustrate, V5.2 includes a protection protocol, allowing for redundancy in the signaling. Usually, the signaling for the 16 E1s is carried on one channel on one link (the primary link). If the signaling link fails, a secondary link is set to take over.

Similarly, SS7 has some similar methods for both traffic sharing redundancy.

It is recommended that for protocol types supporting redundancy, main and redundant signaling paths should be in E1 interfaces, which are in different SDT modules. Consequently, if the module fails in an unlikely event, the communication is not totally lost.

Stillink 3200 supports protocol level redundancy, which are defined in relevant signaling types.

Furthermore, Stillink 3200 has an non-blocked TDM circuit switch and advanced routing algorithms, as well as alternate routing capability. Alternate routing distributes outgoing call traffic over a number of routes leading to the same destination. This method ensures call continuity in case of link failures in the expense of traffic.

Internal Links

Print - Recent Changes - Search
Page last modified on May 21, 2019, at 08:22 AM