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Mbps Gateway
For digital connectivity, via both Digital Trunk Interface (DTI) and Primary
Rate Interface (PRI), North America uses 1.5 Mbps carriers programmed as Pulse Code Modulation Companding u-Law. Internationally, in places like Europe, 2.0 Mbps carriers programmed as Pulse Code Modulation
Companding A-Law are used. To interconnect these two types of switches,
gateways are used. A gateway switch performs conversion from A-Law to
u-Law, and u-Law to A-Law.
The North America 1.5/2.0 Mbps Gateway feature provides support for the
1.5/2.0 Mbps gateway functionality in the North American market, by
introducing software and hardware into North America that is already being deployed in International markets. This feature allows a Meridian 1 PBX to act as a gateway between a 1.5 Mbps Meridian 1 or Central Office switch programmed as u-Law, and a 2.0 Mbps Meridian 1 or Central Office switch programmed as A-Law. The Meridian 1 performs the conversion from A-Law to u-Law, and u-Law to A-Law.
Note 1: For a Meridian 1 to Meridian 1 connectivity, both switches must
be running Release 24 software (in LD 17, the RLS prompt must be set
to 24).
Note 2: This feature performs conversion from A-Law to u-Law, and
u-Law to A-Law. It does not provide interworking between the T-1 and
E-1 protocols. Only those features that are equipped on either side of the
gateway will be supported transparently across the gateway.
The 2.0 MBit (E-1) in North America capability allows an added bandwidth
capability to current Meridian 1 PBX customers, by introducing software and hardware into North America that is already being deployed in International markets. The Bearer channel (B-Channel) capability for PRI voice and data is increased from 23 to 30, and the A/B channels for DTI voice and data is increased from 24 to 30. For an nB+D configuration (nB+D is only supported in an MCDN environment, and not supported by QSIG), the B-Channel capability is 480.
Conversion scenarios
Scenario 1 - Gateway u-Law Meridian 1 connected to A-Law
Meridian/CO over an A-Law 1.5 Mbps connection
A North America (1.5 Mbps) Meridian 1 PBX, programmed as u-Law, is
connected to an International (2.0 Mbps) Meridian 1 PBX, programmed as
A-Law. The connection is over an A-Law 1.5 Mbps DTI/PRI link.
In this scenario, the conversion from A-Law to u-Law, and u-Law to A-Law,
is done at the Meridian 1 programmed as u-Law. It is this Meridian 1 PBX
that acts as the 1.5/2.0 Mbps gateway.
Scenario 2 - Gateway u-Law Meridian 1 connected to A-Law
Meridian/CO over an A-Law 2.0 Mbps connection
A North America (1.5 Mbps) Meridian 1 PBX, programmed as u-Law, is
connected to an International (2.0 Mbps) Meridian 1 PBX, programmed as
A-Law. The connection is over an A-Law 2.0 Mbps DTI/PRI link.
In this scenario, the conversion from A-Law to u-Law, and u-Law to A-Law,
is done at the Meridian 1 programmed as u-Law. It is this Meridian 1 PBX
that acts as the 1.5/2.0 Mbps gateway.
Scenario 3 - Gateway A-Law Meridian 1 connected to u-Law
Meridian/CO over an u-Law 1.5 Mbps connection
An International (2.0 Mbps) Meridian 1 PBX, programmed as A-Law, is
connected to a North America (1.5 Mbps) Meridian 1 PBX, programmed as
u-Law. The connection is over a u-Law 1.5 Mbps DTI/PRI link.
In this scenario, the conversion from A-Law to u-Law, and u-Law to A-Law,
is done at the Meridian 1 programmed as A-Law. It is this Meridian 1 PBX
that acts as the 1.5/2.0 Mbps gateway.
Scenario 4 - Gateway A-Law Meridian 1 connected to u-Law
Meridian/CO over an u-Law 2.0 Mbps connection
An International (2.0 Mbps) Meridian 1 PBX, programmed as A-Law, is
connected to a North America (1.5 Mbps) Meridian 1 PBX, programmed as
u-Law. The connection is over a u-Law 2.0 Mbps DTI/PRI link.
In this scenario, the conversion from A-Law to u-Law, and u-Law to A-Law,
is done at the Meridian 1 programmed as A-Law. It is this Meridian 1 PBX
that acts as the 1.5/2.0 Mbps gateway. |