ATM Circuit Emulation

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ATM Circuit Emulation Quotation Request
Metrodata's ATM Circuit Emulation DSU products allow legacy non-ATM applications to be transported across an ATM network.

ATM Circuit Emulation DSU

ATM Circuit Emulation Application Diagram
  • Transport of non-ATM legacy services across an ATM network
  • Wide variety of European & North American interface standards supported
  • User friendly set-up menus - easy to install & configure
  • Comprehensive performance monitoring & diagnostics
  • Integral remote management supporting Telnet & SNMP
  • All units 19 inch rack-mountable, 1U high
  • Optional universal AC or -48VDC power supply

Product Variants

The drive towards converged network infrastructure means that there is often a requirement to transport legacy non-ATM applications such as PBX or broadcast video over a converged ATM network. Two options exist: either to replace or upgrade the legacy equipment to support native ATM interfaces which can be very expensive and disruptive, or to use an ATM Circuit Emulation (CE) DSU to provide the conversion function at an economic cost. ATM circuit emulation products are available for converting a wide range of legacy interfaces including E1, E2, E3 and DS3 to the common fibre and copper interfaces supported by ATM equipment including E3, DS3 and STM1/OC-3.

The ATM circuit emulation DSU is a 2-port device that segments the legacy traffic into a stream of ATM cells, which are then transported via a permanent virtual connection (PVC) across the ATM network. At the far end the ATM circuit emulation DSU recover the original clock and reassembles the original bit-stream. An integral ATM cell buffer allows for transient traffic bursts without loss of data. This segmentation and reassembly processes is defined in the ITU I 363.1 AAL.1 specification.

The ATM circuit emulation DSU has built in diagnostic loops which segment the link and assist in locating device, cabling or network faults. Extensive performance monitoring statistics are also gathered and stored for 24 hours. This provides a substantial database for assessing the performance of the network, which can be used to identify alarms, errors or data loss. Front panel LEDs also give indication of major and minor alarms.

The default configuration is sufficient to get most installations applications operational, making this a truly plug and play device. Configuration can be performed via a menu driven console port, or via an integrated LM1100 SNMP enabler port which offers substantial Telnet and SNMP capability.

The main fibre interfaces supported are as follows:

  • 1300nm multimode offering transmission distances up to 5km over multimode fibre
  • 1300nm singlemode short haul offering transmission distances up to 30km over singlemode fibre
  • 1300nm singlemode long haul offering transmission distances up to 70km over singlemode fibre

Using fibre optics these products extend the operating distance for an STM-1/OC-3 interface to 5km using low cost multimode fibre, or to either 30km or 70km using singlemode fibre. Despite these quoted maximum operating distances, specific installations may only operate over lower distances due to the variations in losses of different types of fibre cable, the use of connecting fibre cables, or patch panels. When operating over 50% of the maximum distances it is advisable to calculate all fibre optic connector and cable losses and compare these with the fibre optic loss budget specified for this product.

As standard fibre ports are supplied with SC connectors and operate at a nominal wavelength of 1300nm. Other wavelengths are available on request, e.g. 850nm, 1550nm, 1550/1300 WDM. Other connector options are also available on request, e.g. ST, FC.


ATM Circuit Emulation Application Diagram

This application shows how a pair of ATM circuit emulation DSU products can be used to transport an E1 link between two PBX systems over an ATM network, even though the connections into the ATM network at either end are different.


Port G.957
Interface Dual SC Singlemode 8/125um
Wavelength 1310um
Tx Power -8 dBm to -15 dBm
Max Rx input power -8 dBm
Rx Sensitivity -8 to -31 dBm
Optical Loss Budget -15-(-31) = 16dB
Port G.957
Interface Dual SC Singlemode 8/125um
Wavelength 1310um
Tx Power 0 dBm to -5 dBm
Max Rx input power -8 dBm (may need attenuator
Rx Sensitivity -8 to -34 dBm
Optical Loss Budget -5-(-34) = 29dB
Port G.957
Interface Dual SC Multimode 62.5/125um
Wavelength 1310um
Tx Power -14 dBm to -19 dBm
Max Rx input power -14 dBm
Rx Sensitivity -14 to -30 dBm
Optical Loss Budget -19-(-30) = 11dB
Physical BNC (75 ohm) balanced
Cable 75 ohm co-ax
Encoding CMI
Cable Lengths RG59 = 70m, UR202 = 80m
Physical RJ45 (120 ohm) unbalanced
Cable 75 ohm STP
Encoding NRZ
Cable Lengths RG59 = 70m, UR202 = 80m
Rate 155.52Mbps per G.957
Cable Sonet/STS-3c SDH/STM-1 per G.709
Encoding I.432
Clocks Internal, Loop, Though
Physical BNC (75 ohm), G.703, HDB3
Rate 2.048Mbps +/- 50ppm per G703
Framing G704
High Level Framing ETS300-213 or G804
Jitter Per G823
Clocks Internal, Loop, Through
Physical BNC (75 ohm), G.703, HDB3
Rate 8.448 Mbps +/- 30ppm per G703
Framing G804, G832
PLCP None
Jitter Per G823
Clocks Internal, Loop, Through
Physical BNC (75 ohm), G.703, CMI
Rate 34.368Mbps +/- 20ppm per G703
Framing G804, G832
PLCP None
Jitter Per G823
Clocks Internal, Loop, Through
Physical BNC (75 ohm), G.703, CMI
Rate 139.264Mbps +/- 15ppm per G703
Framing G804, G832
PLCP None
Jitter Per G823
Clocks Internal, Loop, Through
Physical BNC (75 ohm), G.703, CMI
Rate 44.736Mbps +/- 20ppm per G703
Framing T1.107/107a
PLCP Tr-TSV 000 773
Jitter Per G823
Clocks Internal, Loop, Through

Environment

Temp 0-50 deg
Humidity 0-95% RH, non condensing
Pressure 86-106 kPa

Power Supply

AC Mains 100-250 VAC, 50-400Hz, 250mA, IEC connector
DC Power -36 to -72 VDC, 200-100mA

Packaging

Type 1U, 19 inch rackmount
Dimensions 425 x 213 x 44 (W x D x H)

Compliance

Safety EN60950
EMC EN55022, EN50082
Management RFC1213 (MIBII), RFC1495 (Telnet), RFC1157 (SNMP), RFC1406 (DS1/E1),

RFC1407 (DS3/E3), RFC1595 (Sonet), RFC1215 (Traps)
Statistics G.821, AT&T54016:15min, 24hr totals

Status & Diagnostics

Loopbacks Local per direction on the ATM port
L0/1 Stats Transmission faults
L2 Stats Cell throughput, good cells, bad cells, corrected cells, reassembly problems

Alarms

Line Major, minor
UNI ATM UNI fault

Part Number
Electrical Network Interfaces 100-250 VAC Mains -48 VDC Power
E3 - E1 CE 80-11-002 80-23-002
E3 - E2 CE 80-11-009 80-23-009
DS3 - E1 CE 80-11-003 80-23-003
DS3 - E2 CE 80-11-010 80-23-010
DS3 - E3 CE 80-11-016 80-23-016
STM1 RJ45NE - E1 CE 80-11-038 80-23-038
STM1 RJ45NE - E2 CE 80-11-039 80-23-039
STM1 RJ45NE - E3 CE 80-11-040 80-23-040
STM1 RJ45NE - DS3 CE 80-11-041 80-23-041

Part Number
Fibre Network Interfaces 100-250 VAC Mains -48 VDC Power
STM-1 MM SC - E1 CE 80-11-026 80-23-026
STM-1 MM SC - E2 CE 80-11-028 80-23-028
STM-1 MM SC - E3 CE 80-11-030 80-23-030
STM-1 MM SC - DS3 CE 80-11-032 80-23-032
STM-1 SM SH SC - E1 CE 80-11-027 80-23-027
STM-1 SM SH SC - E2 CE 80-11-029 80-23-029
STM-1 SM SH SC - E3 CE 80-11-031 80-23-031
STM-1 SM SH SC - DS3 CE 80-11-033 80-23-033
STM-1 SM LH SC - E1 CE 80-11-034 80-23-034
STM-1 SM LH SC - E2 CE 80-11-035 80-23-035
STM-1 SM LH SC - E3 CE 80-11-036 80-23-036
STM-1 SM LH SC - DS3 CE 80-11-037 80-23-037

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