Datasheet

Data Sheet
© 2009 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information. Page 4 of 6
The ATM DS3/E3 hardware “shapes” the VC to the specific parameters using a wheel-based scheduling algorithm
to ensure fairness across the ATM interface. In the event that two cells compete for the same time slot, the VCs are
prioritized in the following order (starting with highest priority): 1) CBR; 2)rt-VBR; 3)nrt-VBR; 3) ABR; and 4) UBR.
OAM cells and signaling has the priority higher than any of the service classes. Prioritizing the VCs in this manner
ensures that the high priority and guaranteed traffic have precedence over the best-effort traffic.
To provide further flexibility, the ATM DS3/E3 allows each of these parameters to be set over a wide range of small
increments. Please refer to Table 4 for the Traffic Shaping Granularity supported on this module.
Table 4. Traffic Shaping Granularity
Parameter Range Increments
PCR 64 kbps to line rate 64 kbps
SCR 64 kbps to line rate 64 kbps
MBS
●
<32 up to 4 Mbps
●
<200 up to line rate
One cell
Note: Although configuration to line rate is allowed, line rate is only reached with large packet sizes.
Extended Virtual Connections Capabilities
The ATM DS3/E3 supports up to 1024 Virtual Connections (VC) and up to 256 Virtual Path (VP). Any combinations
of VC and VP can be supported up to a maximum number of 1024 VC/VP combinations. These VCs can be either
Permanent Virtual Connections (PVC) which are created manually or Switched Virtual Connections (SVC) created
through point-to-point and point-to-multipoint UNI signaling. Table 5 provides Interface Specification details. Table 6
provides LED Indicator description.
Table 5. Interface Specifications
Interface Rate Connector Type Wavelength Maximum Distance
DS3 44.736 Mbps BNC Coaxial 450 ft.
E3 34.368 Mbps BNC Coaxial 1250 ft.
Note: The DS-3 version provides adaptive equalization for 0-450 ft. of cable and provides loopback capability.
The E3 version provides adaptive equalization for 0-1250 ft. of cable and also provides loopback capabilities.
The DS-3 version also has the ability to support line build-out for cable lengths of less than 50 ft. or greater than
50 ft., as required.
Table 6. LED Indicators
ATM NM LED Port Status Function
Enable Green Indicates the ATM NM is successfully inserted and has established communications to the PCI bus. It is
ready to accept CLI commands
RCLK Green Indicates that a receive clock has been detected
FERF Yellow The framer has detected a Far End Receive Failure
OOF Yellow The framer has detected an Out of Frame occurrence
AIS Yellow The framer has detected an Alarm Indication Signal