RAD
IPmux-24 TDM Pseudowire Access Gateway
TDM Pseudowire Access Stand Alone Unit
Key-Points of the RAD IPmux-24 TDM Pseudowire Access Gateway
• Comprehensive support for pseudowire/circuit emulation standards including TDMoIP, CESoPSN, SAToP, CESoETH and HDLCoPSN
• Industry-leading adaptive clock recovery mechanism suitable for cellular backhaul over packet-based networks
• Carrier-class/environmentally hardened device
• Extensive OAM and performance monitoring capabilities
• Three auto-detecting Gigabit or Fast Ethernet SFP- or UTP-based ports, and one, two or four TDM service ports
IPmux-24 provides legacy services over
packet networks. The device converts the
data stream from its user E1/T1 ports into
packets for transmission over the
network. These packets are transmitted
via the RAD IPmux-24 Ethernet network port to
the PSN. A remote pseudowire device
converts the packets back to their original
format.
TDM Pseudowire Functionality With the RAD IPmux-24
Pseudowire Functionality
The ASIC-based architecture provides a
robust and high performance pseudowire
solution with minimal processing delay.
The unit employs various pseudowire
encapsulation methods, including TDMoIP,
CESoPSN, SAToP, CESoETH (MEF 8) and
HDLCoPSN.
Proper balance between PSN throughput
and delay is achieved via configurable
packet size.
A jitter buffer compensates for packet
delay variation (jitter) of up to 180 msec
in the network.
Pseudowire Traffic Protection
Pseudowire traffic can be backed up at
the pseudowire connection level. This
allows setting a different path for the
primary and secondary PW bundles. Both
bundles can be routed to the same or
different destinations and operate in the
1+1 and 1:1 modes.
In 1:1 redundancy with two remote
devices the PW bundles in the remote
units operate in “mate” mode. In this
mode each device monitors traffic on a
mate bundle and transfers data only when
the other bundle is inactive.
OAM With the RAD IPmux-24
OAM
The unit uses the end-to-end Ethernet
OAM protocol for proactive connectivity
monitoring, fault verification, and fault
isolation, according to the IEEE 802.1ag
and ITU-T Y.1731 requirements.
In addition, RAD’s TDM PW OAM
mechanism verifies connectivity, measures
round trip delay and prevents pseudowire
configuration mismatch.
Bridge
RAD IPmux-24 features an internal bridge,
operating in VLAN-aware and
VLAN-unaware modes.
VLAN stacking is used for traffic
separation between different users or
services, by defining a service provider
VLAN ID per customer or service. When
VLAN stacking is used, a service provider
VLAN tag is added to the user traffic and
removed from network traffic. Both
service provider VLAN ID and service
provider VLAN priority can be defined.
Quality of Service Using the RAD IPmux-24
IPmux-24 provides four priority queues for
each port or pseudowire traffic flow. User
traffic can be prioritized according to
VLAN priority, DSCP, IP Precedence or per
port.
Outgoing pseudowire packets are
prioritized over Ethernet network by being
assigned a dedicated VLAN ID (802.1q)
and marked for priority using 802.1P bits.
Over IP networks, the outgoing
pseudowire packets are marked for
priority using DSCP, ToS, or Diffserv bits
and over MPLS networks, EXP bits are
assigned to a specific MPLS tunnel.
Timing and Synchronization
Simple Network Timing Protocol:
IPmux-24 employs Simple Network Time
Protocol (SNTP) for propagating and
receiving time information on a network,
according to SNTPv4 (RFC 4330)
requirements. SNTP is used to configure
data and time by learning the information
from a single or multiple SNTP servers. The
clock can be configured to a local time by
defining UTC and DST offsets.
Pseudowire Timing
End-to-end synchronization between circuits is maintained by deploying advanced clock recovery mechanisms. Clock recovery conforms to G.823 and G.824 traffic interface using G.8261-defined scenarios. Advanced clock recovery conforms to G.823 synchronization interface using G.8261-defined scenarios and achieves 16 ppb clock accuracy. The system clock ensures a single clock source for all TDM links. The system clock uses master and fallback timing sources for clock redundancy. IPmux-24 also provides system clock input and output via an optional external clock port.
IPmux-24 Management and Security
IPmux-24 can be configured and
monitored locally via an ASCII terminal, or
remotely via Telnet/SSH, Web browser or
RADview.
Management traffic can run over a
dedicated VLAN.
The RADview Service Center and Element
Manager packages control and monitor
pseudowire devices and circuits. The
Service Center’s intuitive GUI, “point andclick” functionality and easy-to-follow
wizards increase the efficiency and
accuracy of the service provisioning
process.IPmux-24 performs RADIUS client
authentication. Using SSH and SSL
encryption protocols allows secure
communication over potentially insecure
IP-based networks.
The Syslog protocol is used by IPmux-24
to generate and transport event
notification messages over IP networks to
the central Syslog server. The Syslog
operation is compliant with the RFC 3164
requirements.
SNMPv3 support introduces a user-based
security model, enhances authentication
and encryption techniques, and ensures
management traffic security.
Resiliency
Ethernet Ring Topologies:
A G.8032 Layer-2 Ethernet ring is used by
IPmux-24 for traffic protection. This
technology builds a logical ring, defined as
a set of IEEE 802.1-compliant bridges, and
protects against link and node failures. To
achieve this, every node in the ring has
two bridge ports connected to adjacent
nodes.
The ring itself is constructed
independently of the transport technology
used at the server layer.
In addition, the unit employs Resilient
Ethernet Ring technology to construct a
self-healing Ethernet fiber ring topology
(ring resiliency is similar to that of
SDH/SONET networks). In case of link
failure on any segment of the ring, the
pseudowire traffic is rerouted within
50 ms. A single ring supports up to
16 nodes.
Ethernet Link Protection:
The unit performs link aggregation (LAG)
based on 802.3ad requirements.
Dual homing technology (1:1) allows
IPmux-24 to be connected to two
different upstream devices.
Monoitoring and Diagnostics
Fault propagation initiates service port
alarms, e.g. E1/T1 LOS, to reflect network
fault conditions. Alarms detected at
service ports are propagated to the
remote pseudowire device via the packet
network.
Diagnostic loopbacks can be activated
inband.
Ethernet and IP-layer network condition
statistics, such as packet sequence errors
(loss or misorder) and packet delay
variation (jitter), are monitored and stored
by the device.
The carrier-class version of IPmux-24
includes an alarm relay mechanism. The
minor and major alarms are forwarded to
a remote alarm device via dedicated pins
of the external clock RJ-45 connector.
