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sipvoippbxtelecommunication

PRI Trunks on IAD

Please clarify a few questions regarding the below scenario -

A service provider is providing a business "ABC Limited" two PRI trunks on a single IAD.

  1. Should the IAD be always a 48-port IAD or could it be a 24-port IAD?
  2. Assuming it's a 24-port IAD, what I'm unable to understand here is that if the device has only 24 ports then how will it allow 46 simultaneous call?
  3. Is there any limitation placed on the number of analog telephone devices that could use a single IAD assuming a PBX is used between IAD and telephone devices?
  4. Can the IAD be used without a PBX? If yes, then what should be the total number of analog telephone devices that could be attached to the IAD?
Solution

  • I provide a brief overview of an IAD below that will help clarify the answers to the questions posted.

    Should the IAD be always a 48-port IAD or could it be a 24-port IAD?

    Hardware-wise, the provider will provide a Voice handoff(Analog or Digital, PBX or Analog phone) and this will depend on the Data Pipe being installed. As an example, utilizing Telco Data, a 1.5 Meg T1 with 24 ports allowed for Voice channelization, if ALL ports are in use, this will utilized ALL the Bandwidth and not allow for any data to be used. So, 48-port IAD can be configured, only if the Data Pipe being installed is (2) bonded 1.5 Meg T1's.

    Assuming it's a 24-port IAD, what I'm unable to understand here is that if the device has only 24 ports then how will it allow 46 simultaneous call?

    You are correct. You will only have 24 voice channels available in a 24 port configuration. The handoff can be to a PBX can be Analog Trunks(can have analog telephone devices connected to these) or a PRI protocol.

    Is there any limitation placed on the number of analog telephone devices that could use a single IAD assuming a PBX is used between IAD and telephone devices?

    When talking analog telephone devices only, then, a 1 to 1 ratio has to be considered in the case of an Analog Trunk handoff.

    Can the IAD be used without a PBX? If yes, then what should be the total number of analog telephone devices that could be attached to the IAD?

    Again, in an Analog Handoff, a 1 to 1 ration is what you will need to consider.

    NOTE: Integrated Access Device (or IAD) provided by the Local Telecom Provider can be deployed with multiple configurations. Its primary purpose is to aggregate multiples channels of data to support Voice and Data services to a carrier or service provider using one Data pipe onsite. When no Voice Channels are in use, the total capacity of the pipe can be utilized for Data.

    Dynamically, the pipe will allow Voice channels(or ports) to be available when requested by the PBX onsite/analog device attached to the IAD or when an PSTN caller dials into the PBX/analog device. The Data Pipe will dynamically adjust to allow less Data to be used on the shared pipe to allow the Voice Channel connect. This is approximately 64k of bandwidth PER Voice Channel.