Purpose of TDM over Packet technology

Telecom companies and enterprise users can save significant 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 2 x T1 over Ethernet (VCL-T1oP) multiplexer may be used to provide legacy TDM services over Ethernet optical fiber, or wireless Ethernet/IP networks.

How the TDM over Packet (2 T1 Port FE 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' (2 T1 Port FE 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)

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

• Redundant power supply inputs.

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

• EMI / EMC Complaint

• Real Time battery backed clock with life in excess of 10 Years

• Power over Ethernet (PoE) - Optional

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 2 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 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.

• CESoPSN payload mechanism feature allows the user to optimize the packet switched network by limiting its usage to the corresponding number of timeslots carried by a 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) addressing.

• 100 ohms balanced T1 interfaces.

• T1 Loopback facility for testing and diagnostics.

Key Features - Ethernet / IP Network Interface

• Optical SFP based (100Base-FX) and Electrical (100Base-T) Ethernet port and PoE options

• 4 x 10/100BaseT Copper Ports.

• 2 x 10/100BaseT Copper Ports, 2 x 10/100BaseT Ports with PoE.

• 2 x 100BaseFX Optical Fiber Ports, 2 x 10/100BaseT Copper Ports.

• 2 x 100BaseFX Optical Fiber Ports, 2 x 10/100BaseT Ports with PoE.

• VTC Virtual Cable tester on all PHY (Electrical Ethernet) Ports.

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

• Supports drop and insert applications.

• 1+1 Ethernet Link Redundancy (Hitless) Redundant Link Protection.

• Supports QoS, 802.1p based packet priority.

• Port Control Egress Mode (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 2048 Bytes.

• Port based and Tag based VLANs Supports 1-4095 VLAN Ids.

• Supports Ethernet rate limiting on each port.

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

Key Features - System Management, Monitoring and Alarm Interfaces

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

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

• Port Trunking.

• 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.

• In band VCCV ARP.

• Broadcast DA.

• 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.

OAM: Operation and Management Ports

• RS232 (DB9) Serial Port.

• 10/100BaseT Ethernet Management for In-band remote access.

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.

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.