Instruction manual

Separation of Bearer and Signaling
Issue 4 May 2003 125555-233-767
Separation of Bearer and Signaling
The Separation of Bearer and Signaling (SBS) feature provides a low cost virtual
private network with high voice quality for customers who cannot afford private
leased lines. SBS provides a DCS+ VPN replacement for those customers needing
Dial Plan Expansion (DPE) functionality.
NOTE:
QSIG works with six-digit and seven-digit dial plans, but DCS does not. In
addition, QSIG does not work over VPNs, but DCS does. The SBS feature
combines the capabilities of both QSIG and DCS, allowing for six-digit and
seven-digit dial plans working over VPNs.
The SBS feature supports:
■ QSIG private networking signaling over a low cost IP network
■ Voice (bearer) calls over public switched network
■ Correct association between QSIG feature signaling information and each
voice call
You must always use AAR/ARS/UDP to originate an SBS call. You cannot use a
Trunk Access Code / Dial Access Code to originate an SBS call.
Proper administration and configuration is required for SBS calls to work
correctly. This includes:
■ Fields in the SYSTEM-PARAMETERS FEATURES form, a field on the TRUNK
GROUP
form, and a Station type called an SBS Extension (an
extension number without hardware assigned to it that is used to associate
the separate bearer and signaling calls).
■ Customers must allocate a sufficient number of SBS extensions based on
expected SBS traffic volume. The same applies to SBS trunk group
members.
■ Each administered SBS extension must correspond to a DID/DDI number
obtained from a local service provider.
NOTE:
Obtaining a DID/DDI number for each SBS extension is not
necessary if the Feature Plus Pseudo DID feature is available.
■ In remote office configurations or other remote gateway configurations
with limited direct network access, these DID/DDI numbers should be
obtained from a service provider that is local to the controlling gateway
server, not local to the remote office/gateway. This eliminates excessive
traffic through the remote office/gateway to its controlling gateway server.