Purpose of TDM over Packet technology
 

Telecom companies and enterprise users can save network and equipment cost and generate additional revenue by offering different types of services over a single packet-switched infrastructure by the use of T1oP equipment. The T1oP equipment is also suitable for connecting to Ethernet / packet wireless equipment to achieve fast deployment of T1 services over wireless Ethernet networks. One particular application is to build T1 links with low cost Wireless LAN bridges, replacing expensive TDM / T1 microwave radios.

The 8 x T1 over Ethernet (VCL-T1oP) multiplexer may be used to provide legacy TDM services over Gigabit Ethernet optical fiber, or wireless Ethernet/IP networks.

How the TDM over Packet (8 T1 Port GE Version) equipment works

The T1 data streams received on the T1 interfaces are converted by the T1oP engine of the T1oP equipment to Ethernet data packets (of a fixed size) and transported over the Ethernet network with UDP / IP, MEF or MPLS headers. At the receiving end the T1oP reconstructs the original data streams by removing the IP, MEF or MPLS headers and converts the Ethernet data packets back to T1 frames using highly reliable and accurate clock recovery mechanism. The 'VCL-T1oP' (8 T1 port GE Version) offers the user a choice of standard, T1 to packet and packet to T1 conversion mechanisms that include SAToP and CESoPSN technologies.

Hardware Highlights

• 19-Inch rack mountable

• 1U form factor (44mm high)

• 1+1 Redundant Power Supplies, AC and DC, or AC plus DC

• Redundant power supply inputs

• Extended Temperature Range: (-20⁰ C to +60⁰ C)

• EMI / EMC Complaint

• Real time battery backed clock with life in excess of 10 years

T1 Clock recovery and synchronization techniques:

• Adaptive Clock Recovery (ACLK)

• Recovered Clock (RCLK) / Loop-Timed Clock

• Asymmetrical (One-Clock and Two-Clock) Clock

• Synchronization to an External Clock (ECLK)

• Synchronization to an Internal Clock

• Automatic clock priority selection with fall back

• Plesiochronous Clocking.

Key Features - T1 and T1oP Interface

• Supports 8 independent T1 interfaces.

• Internal, External, Adaptive, Recovered clock and Asymmetrical (One-Clock and Two-Clock) options for the T1 TDM port synchronization. Automatic clock priority selection with fall back

• Absolute and Differential times tamps.

• Jitter and Wander conforms to G.823 / G.824 and G.8261 and TDM specifications.

• Supports three T1 framing modes - Framed, Unframed and Multi-framed with CAS signaling.

• Supports point-to-point, point-to-multipoint and drop and insert applications.

• Supports IETF-PWE3 (pseudo-wire), SAToP and CESoPSN transport mechanisms.

• Supports CESoPSN payload mechanism to support the fractional T1 with data rate of 64Kbps to 1.544Mbps (DS0 timeslot level). User configurable data rate from 64kbps to 1544kbps, in steps of 64kbps.

• ESoPSN payload mechanism feature allows the user to optimize the packet switched network by limiting its usage to the corresponding number of timeslots carried by an T1 channel.

• Supports SAToP payload mechanism to transport full T1 (transparent to the structure of the TDM frame useful for transporting framed / unframed T1 channels).

• Supports network latency / packet delay variation / jitter buffer of up to 512ms.

• Supports IP, MPLS and MEF8 (Metro Ethernet) tagging.

• RJ45 - 120 ohms balanced T1 interfaces. Optional 75 Ohms BNC interface (120 Ohms to 75 Ohms interface converter cables provided).

• T1 Loopback facility for testing and diagnostics.

Key Features Ethernet / IP Network Interface

• Switching Capacity upto 6 Gbps, non-blocking.

• 4 GigE Ports.

• Optical SFP based (1000Base-FX) and Electrical (10/100/1000Base-T) Ethernet port options.

• 2 x 10/100/1000BaseT Copper Ports.

• 2 x 1000BaseFX Optical Fiber Ports.

• Point-to-point and point-to-multipoint applications based on IP addressing.

• Supports drop and insert applications.

• Port Control Ingress Rate Limiting.

• 1+1 Hitless Ethernet Link Redundancy  

• Port Trunking.

• Spanning Tree Protocol.

• IGMP Snooping

• Supports QoS, 802.1p based packet priority.

• Tagged/Un-Tagged/Un-Modified 802.1Q Mode.

• Q-in-Q Tagging.

• User configurable MTU (T1oP payload) packet size. May be configured from 1 to 1800 Bytes.

• Switch supports jumbo frame sizes of up to 9000 Bytes.

• Port based and Tag based VLANs.

• Single / Double 802.1 VLAN tagging (Q in Q VLAN Tagging) user configurable.

• Supports QoS on 802.1p based packet priority.

• Supports Packet priority assignment (IP Diffserv / DSCP).

• UDP-specific “Special” Ethernet type.

• In band VCCV ARP.

• Broadcast DA.

System Management, Monitoring and Alarm Interfaces

• NMS (Network Management System) to monitor multiple units from single Central Location.

• External Alarm - Dry contact relay alarms are also available at rear of the system to connect the system to an external alarm.

• Supports system temperature monitoring with High Temperature and Low Temperature alarms and SNMP Traps.

• Supports SNMP V2 Monitoring and Traps.

• UDP-specific “Special” Ethernet type.

• Self-test for checking system errors upon system bootup.

• Event Logging.

• Clock Performance Alarms.

• Network Performance Alarms.

• Network Performance Monitoring and Diagnostics.

• Online / remote upgrade of firmware.

System Access, Control and Management Options

• Telnet.

• CLI Control Interface (HyperTerminal or VT100).

• SNMP V2 Traps (MIB File provided).

• Windows based GUI (Graphical User Interface) for easy configuration, management and access. Ability to monitor multiple units from a single NMS.

• Password Protection.

OAM: Operation and Management Port

• RS232 Serial Port.

• USB COM Port.

• 10/100/1000BaseT Ethernet for remote access.

Application Diagrams

• Application 1: T1oP in Cellular Backhaul

• Application 2 : Typical Application Diagram in Wireless Network

• Application 3 : Typical Application Diagram in Wireless Network - 1+1 Link Redundancy

• Application 4 : Typical Application Diagram in Wired Network

• Application 5 : E1s and Gigabit Ethernet Traffic over a Packet Switched Network