What is a T1 or E1?

T1 and E1 refer to telephone trunks that carry digitized voice in Time Domain Multiplexed (TDM) channels. T1 based interfaces are pre-dominantly used in USA. Each T1 has 24 voice ports.

E1 based interfaces are pre-dominantly used in Europe, Asia and Latin America. Each E1 has 30 voice ports.
One voice port equates to one phone call.



What is an ISDN PRI?

T1 ISDN PRI refers to a T1 based trunk that uses 23 bearer time slots and 1 signaling time slot. It is also popularly referred to as 23B + D.

E1 ISDN PRI refers to an E1 based trunk that uses 30 bearer time slots and 1 signaling time slot. It is also popularly referred to as 30B + D.



What is a VoIP/SIP trunk?

Voice over IP refers to carriage of voice calls over the Internet. Session Initiation Protocol (SIP) is a signaling protocol that is used for setting up VoIP connections. The VoIP/SIP trunk operates over a standard Ethernet interface.



What interfaces does USN support?

USN supports the following TDM interfaces:

  • T1 ISDN PRI
  • T1 E&M Wink Start (CAS)
  • E1 ISDN PRI
  • E1 R2MF

USN supports the following Voice over IP interface:

  • VoIP/SIP over Ethernet.
  • H.323 over Ethernet



What is the capacity of a USN

A USN can handle up to 16 T1 or E1 trunks per chassis. That equates to 384/480 voice channels. The available voice channels can enter/exit the system either over T1/E1 lines or over VoIP Ethernet interface or shared between the two. For example, following configurations are possible:

  • 384 T1 TDM ports and 0 VoIP ports
  • 480 E1 TDM ports and 0 VoIP ports
  • 0 TDM ports and 480 VoIP ports
  • 240 E1TDM ports and 240 VoIP ports



What is the incremental capacity of a system?

  • For systems equipped with T1 and VoIP interfaces, the port capacity can be increased from 24 to 384 in increments of 24. This applies to both TDM and VoIP capacity.
  • For systems equipped with E1 and VoIP interfaces, the port capacity can be increased from 30 to 480 in increments of 30. This applies to both TDM and VoIP capacity.



We use legacy TDM based PBX system. What do we need to interface with a USN?

You will need to equip the PBX with additional T1/E1 CAS or ISDN cards to connect one or more T1/E1s between the PBX and the USN.



How should the trunking be set up between the PBX and the USN?

You will need a bi-directional Tie trunk between the PBX and the USN.

Inbound to USN: Set up a hunt group with number of channels equal to number of ports on the USN. For example, for a 48 port system set up a hunt group with 48 channels.

Outbound from USN: Calls originating from USN will be received by the PBX which in turn will route them to either internal extensions or to external PSTN numbers.



What is the default configuration of a CAS T1 trunk on the USN?

The default configuration is: E&M, Wink Start, DTMF, DNIS and No ANI.



What is the default configuration of an ISDN T1 trunk on USN?

The default configuration is: NI-2, User Side, DNIS and ANI.



We use an IP PBX system. What interfaces do we need on the USN?

In an all IP environment the USN will interface with the IP PBX over a VoIP/SIP Trunk. The USN will send/receive voice calls towards/from the IP PBX over this interface.



How should the VoIP trunk be configured between the PBX and the USN?

You will need a bi-directional SIP based Tie trunk between the PBX and the USN.

Inbound to USN: Set up a hunt group with number of channels equal to number of VoIP ports on the USN. For example, for a 48 VoIP port system set up a hunt group with 48 channels.

Outbound from USN: Calls originating from USN will be received by the IP PBX which in turn will route them to either internal extensions or to external PSTN numbers. The external connectivity to the PSTN can be via a TDM based T1 trunk or via a VoIP carrier.



What if the power is knocked out at our location?

XOP Networks recommends that the equipment be deployed with a minimum of 1000 VA UPS. That will keep the unit running for 1 hour in case of loss of power.

In case of mission critical applications, our customers deploy two geographically redundant systems. The system’s software keeps both sides synchronized 100% of the times using real time data base replication. In case of extended power outage, the surviving system can be used for handing emergency situations.

As a further back up, XOP Networks can keep a copy of customer’s database on its customer care servers and allow use of that server during emergency situations. Please contact XOP Networks Customer Support department if that is required.



How do I know that my USN system is up and running?

If you dial the main bridge number and hear a prompt requesting you to enter a PIN, the system’s voice application is in operational state.
If you can log into the system that means all networking aspects between your computer and the USN server are operational.



Can I place my company’s logo on the Web Portal?

A customer can upload their own logo in place of XOP Networks logo via the System Configuration page on the admin interface.



Does the system generate any reports automatically?

The system automatically generates a usage and system health report every midnight. It captures previous day’s usage data. The report also tabulates month to date and year to date reports. These reports give sufficient information to the administrator so that he/she can determine if additional capacity is needed. In addition to the usage report, data is provided on the status of various components of the system such as Hard disk drives, Operating system etc.



What type of reports can I generate as an administrator?

A system administrator can set up various queries to determine usage by individual moderators, by service type etc.



How do I know when I need to add ports?

Different businesses have peaks at different times. The administrator can watch all calls on the Real View link. Visually, he/she will be able to tell if the system is running close to its maximum capacity or not. With Release 5.0, the USN will also provide a histogram that displays number of ports in use by the hour.