Key points of MiTOP-E1/T1- TDM circuit emulation over a packet-switched network (PSN) with CESoPSN (RFC 5086)
and SAToP (RFC 4553) payload encapsulation
ASIC-based architecture for minimizing processing delay
Advanced clock distribution mechanism, and configurable jitterbuffer
Comprehensive OAM and performance monitoring
The RAD TMiTOP-E1/T1 is a TDMpseudowire (PW) access gateway extending
TDM-based services over packet-switched networks. Housed in a Small Form-Factor Pluggable
(SFP) enclosure, it is designed for quick and simple insertion into any 100BaseFx
Ethernet device port with an MSA-compatible socket.
MiTOP-E1/T1 is simple and cost-effective alternative to external, standalone
gateways or conversion cards for each user device, saving on space, power consumption, cabling, and simplifying
MiTOP-E1/T1 gateway provide a legacy over PSN solution for transmitting E1/T1 streams
over packet switched networks. The device converts the data stream from its user
E1 / T1 ports into packets for transmission over the network. The addressing scheme of these packets is
UDP/IP, MPLS or MEF. These packets are transmitted via a 100BaseFx port of the host device to the PSN. A remote
pseudowiregateway converts the packets back to TDM traffic. High-performance ASIC-based buffering
and forwarding techniques are used to achieve minimal end-to-end processing delay.
Configurable packet size allows to achieve proper balance between PSN throughput
and delay. Large configurable jitterbuffer per each
PW connection compensates for the delay variation introduced by the PSN. The gateway supports the following
Payload CESoPSN and SAToP
Network MPLS, MEF, UDP/IP.
SFP ENCLOSURE of the RAD
Housed in a Small Form Factor Pluggable ( SFP ) package, RAD
MiTOP-E1/T1 complies with the Multi-Source Agreement.
Running on power derived from the host device, it requires no additional power supply.
MiTOP-E1/T1 is hot-swappable and features a special release mechanism for easy extraction from the SFPsocket.
For Ethernet networks the outgoing pseudowire packets are assigned a
dedicated VLANID according to 802.1Q
and marked for priority using 802.1p bits.
For IP networks the outgoing pseudowire packets are marked for priority using ToS
(including the DSCP and Diffserv bits). For MPLS networks the outgoing pseudowire packets are assigned to a
specific MPLS tunnel and marked for priority using EXP bits.
Synchronization between TDM devices is maintained, by deploying advanced clock distribution mechanisms. The clocking
Internal the master clock source for the TDM circuit is provided by the internal clock oscillator
Loopback the transmit clock is derived from the E1 / T1 ports receive clock
Adaptive the clock is recovered from the PSN.
Advanced clock recovery conforms to G.823 using G.8261-defined scenarios. Jitter and wander of the recovered
clock are maintained at levels that conform to G.823/G.824 traffic. For adaptive clock recovery, the recovered
clock performance depends on packetnetwork characteristics.
TDMINTERFACE of RAD MiTOP-E1/T1
The TDMport provides connectivity to any standard E1 or T1 device. E1 and T1 interfaces support:
G.703, G.704, framed and unframed modes
SF and ESF framing (T1).
MiTOP-E1/T1 is transparent to all signaling protocols.
RAD MiTOP-E1/T1 FAULT PROPAGATION E1 or T1 loss of signal is propagated by sending an electrical LOS signal to the
100BaseFx port, and is visually indicated by the LOSLED (red) turning on. This in
turn can automatically turn off the LAN link. Turning on/off the packet link is user-configurable (enabled or
The units can be managed using different ports and applications:
Out-of-band via I2C channel (of the SFP edge connector)
Inband via the Ethernetport, using a Web browser.
OAM AND PERFORMANCE MONITORING RADs TDM PW OAM mechanism verifies connectivity and prevents pseudowire
configuration mismatch. The following RFC-2495 E1/T1physical layer performance statistics are available:
BES, ES, SES and UAS.
DIAGNOSTICS USING THE RAD MiTOP-E1/T1
External and internal loopbacks can be used to check TDM link connectivity. Alarms detected during operation are
stored in a buffer holding up to 100 events.
An optional configuration adapter is available for connecting MiTOP-E1/T1 to a PC via a USB 2.0 port.
The configuration adapter is used for the preliminary configuration of the gateways
or software download to the units.