Carrier Access Broadmore 1750 - Manual (Page 172)

7-58 Broadmore 1750 - Release 4.6
Configuration
Unstructured E3-3 SAM
Table 7-13: Unstructured E3-3 SAM Operational Configuration
Item Options Comments
Port Name A descriptive field to identify the port
Port Mode On-line
Off-line This is a status field that can be toggled to off-line, in which case the port will
not be available to make calls and passive SVCs are refused.
Framing G.751
G.832
Unframed G.751 is a European framing standard used for PDH applications.
G.832 is a European framing standard set by the ITU for transporting SDH
elements on PDH network.
Unframed requires a 44.736 Mbps input.
Clock Mode SRTS
Adaptive
Network
BITS Clock
Loop NOTE: SRTS is a proprietary timing algorithm and may ONLY
be used with specific written prior permission from Carrier Access
Corporation. Additional license fees may apply.
SRTS measures the Service Clock input frequency against a network-wide
ATM synchronization clock and sends the difference signals in the AAL1
header to the destination Broadmore 1750 circuit emulation interface. The
different signals are then combined with the network-wide ATM
synchronization clock to re-create the input service clock. If more than one
ATM clock synchronization is present in the network, an alternate timing
recovery method must be selected. For this method to work, the ATM network
must be synchronized to a single network-wide clock source. User equipment
should be configured to internal clock.
Adaptive Timing maintains a pre-defined fill level in the Circuit Emulation
Re-assembly buffer to control the timing output to user equipment. This
method of timing recovery does not require a Synchronous ATM network and
is used in applications where network wide synchronization is not available.
(Synchronous) Network method of clock recovery derives timing from the
ATM Network and propagates it to the CE Service Interface. The ATM
network must be synchronized to a single source clock. User equipment should
be configured to recover timing from the Broadmore 1750 CE service
interface.
(Synchronous) Loop CE interface will derive clock from the attached E3 user
equipment and transmit from the CE interface at that rate. The user equipment
should be configured for Internal timing if the Broadmore 1750 CE service
interface is configured for Synchronous loop.
BITS- (Building Integrated Timing Supply) distributes standard timing to
equipment within the central office. The Broadmore 1750 accepts BITS via
either NIM IOM. The fallback for the primary BITS clock is the other BITS
clock. The fallback for no BITS is the internal clock of the NIM.