Verilink Red Zone Encryption (REMS) (880-502423-001) Product Manual - Manual (Page 27)

Red Zone Encryption Management System (REMS) User Manual User Manual 3-1
Chapter
3
Theory of operation
This section provides technical background on problems with encryption
over service carrier networks and the REMS solution to these problems.
In depth material is presented on how REMS functions are allocated to
and performed by its dual components, the FBR and the BRC. Subjects
covered are framing, alignment, and system communication.
Verilink solves historical problems of encryption over
T1 networks
When using the public telecommunications network to transport a full
bandwidth encrypted signal, two areas have been problematic:
■
positioning the framing bit
■
having access to Black Zone information about performance data,
network alarms, and fault isolation from the Red Zone
Framing
Encrypted T1
signals Transmission of encrypted, full bandwidth T1 signals across the public
switched network has always been a challenge to the communication
engineer. In the past, the carrier furnished a custom T1 facility to
transport encrypted T1 data in an unframed format. In today’s world,
custom T1 facilities are nonexistent or, at best, very expensive.
The challenge to the user is how to economically hand off a framed, full
bandwidth encrypted signal from the secure Red Zone to the carrier in the
non-secure Black Zone. The previously accepted method has been to
reposition the DTE frame bit into the payload before encryption and
insert the network framing sequence into the bit stream after encryption.
This process requires payload bandwidth to transport the DTE framing
sequence to the far end. Transport of the framing information is necessary
to ensure that at the far end, DTE framing is positioned correctly with
respect to the payload.