RICi-155GE Gigabit Ethernet over 2 x STM-1/OC-3c Network Termination Unit
RICi-155GE Connects Gigabit Ethernet LANs over up to two STM-1/OC-3c links
The RICi-155GE from RAD is a state-of-the-art network termination unit (NTU) that bridges
between Gigabit Ethernet networks and STM-1/OC-3c networks, providing simple, efficient, and cost-effective Gigabit
Ethernet connectivity over SDH/SONET networks. The device offers a migration path for connecting future-ready IP
devices to existing SDH/SONET networks at up to 300 Mbps access rates.
RICi-155GE complies with RADs unique set of EtherAccessTM features. This feature
set provides services and carrier backhaul applications over low and high-speed SDH/SONET and PDH circuits, from
fractional and full E1/T1 or E3/T3 over STM-1/OC-3c or STM-4/OC-12 to Gigabit Ethernet.
Typical applications include IP DSLAM backhauling (Figure 1), enterprise connectivity (Figure 2), and
high-bandwidth private line services.
The RAD RICi-155GE is equipped with two STM-1/OC-3c ports with SFP-based optical
interfaces, offering either 300 Mbps with link bonding using VCAT (G.707/Y.1322)
and LCAS (G.7042), or 1+1 link protection mechanism (unidirectional MSP/APS) to increase service uptime. The
unit has two Gigabit Ethernet ports that support Gigabit Ethernet link redundancy based on link
aggregation protocol IEEE 802.3ad. The Gigabit Ethernet ports can be ordered with
SFP-based optical interfaces or 10/100/1000BaseT interfaces.
Flexible traffic mapping with the RAD RICi-155GE
The incoming customer traffic is mapped to the Ethernet flows (EVCs) using the following per-port criteria:
Port-based (All-in-one bundling)
User port + CE-VID
User port + CE-VLAN priority.
Each Ethernet flow can either have a single service assigned to it or up to eight
services that are differentiated by the CE-VLAN P-bits (EVC.CoS).
Traffic is encapsulated with:
Generic Framing Procedure (ITU-T G.7041, ANSI T1-105.02), framed mode
Link Access Procedure for SDH/SONET
(LAPS) protocol following draft recommendation ITU-T X.86.
RAD RICi-155GE - QUALITY OF SERVICE QoS
Different service types require different levels of QoS to be provided end-to-end.
QoS can be defined per subscriber as well as per service. QoS has two aspects: rate
limitation and traffic prioritization.
Two policing mechanisms (upstream and downstream) are applied per service. The policing mechanisms operate according to
the dual leaky bucket mechanism (CIR+CBS, EIR + EBS: two rates, three colors).
For prioritizing user traffic, RICi-155GE features up to four separate queues. The queues handle traffic with different
service demands, such as real-time traffic, premium data, or best-effort data. The preceding capabilities allow service
providers to offer different services and traffic types over the same link.
SDH/SONET Timing Options of RICi-155GE
The user can define the following
SDH/SONET clock sources:
Recovered from STM-1/OC-3c interface.
RAD RICi-155GE SDH/SONET LINK REDUNDANCY
The unit supports a 1+1 link protection mechanism (APS), according to the ITU-T G.841 requirements (unidirectional
MSP). Additional protection is provided by the VCAT and LCAS protocols.
GIGABIT ETHERNET LINK REDUNDANCY
To allow reliable and uninterrupted service, the Gigabit Ethernet ports can be set to work in 1:1 or 1+1 automatic
protection switching mode, according to link aggregation protocol (IEEE 802.3ad).
RICi-155GE MEF COMPLIANCE
RICi-155GE is certified by the Metro Ethernet Forum (MEF) for the following services:
MEF 9: EPL, EVPL
MEF 14: EPL, EVPL
The unit features a user-configurable bi-directional fault propagation mechanism
that notifies local and remote equipment
of faulty conditions. This enables routers and switches on both ends of the link to
RICi-155GE SDH/SONET alarms can optionally propagate and cause the Gigabit Ethernet
link to shut down. The Gigabit Ethernet alarms can also be propagated over the SDH/SONET link.
Management of the RICi-155GE
The unit can be managed with the following ports and applications:
Out-of-band management via Fast Ethernet or RS-232 port
Remote inband management via SDH/SONET or Gigabit Ethernet port.
Remote management is performed using Telnet, Web browser, or an SNMP -based management system.
RICi-155GE supports the following security protocols:
SSL for Web-based management application
SSH for Secure Shell communication session.
These capabilities provide a high level of client-server communication security and
correct user authentication.
RICi-155GE product data sheet (pdf)