ACE-52 Ethernet LAN and TDM Services over ATM Networks
ACE-52 is a Customer Located Equipment (CLE) dedicated for provisioning Ethernet (10/100BaseT) and E1/T1 CES interworking services over an ATM network (see Figure 1). Used as a Network Termination Unit (NTU), ACE-52 provides a demarcation point between the provider’s network and
the customer premises. This enables end-to-end traffic and network management control.
ACE-52 ATM Capabilities
Using the RAD ACE-52, carriers assign each virtual connection (VC) to different service classes, define the QoS parameters and shape the ATM egress traffic accordingly (CES VCCs support only CBR traffic). By limiting the ATM port egress rate, carriers control the total bandwidth provided to their users. The following service classes are supported: CBR, VBR, GFR, UBR and UBR+. ACE-52 allows up to 32 VCCs to be established and used simultaneously.
At the ATM egress, the RAD ACE-52 provides two levels of traffic management:
Shaping per VC
Rate limiting of the entire traffic coming out of the ATM port.
ACE-52 maps QoS parameters according to the VLAN priority or ToS field. QoS is supported in two modes:
Mapping to different VCCs (with different traffic descriptors) of the same bridge port according to configured priority
Mapping to four strict-priority VCC queues according to configuration.
The ATM OAM features reduce operational costs by providing end-to-end traffic manageability and fault localization. OAM functionality complies with ITU-T I.610, and includes:
AIS/RDI – system indication for local or remote fault conditions. In case these indications are detected in the network interface, ACE-52 sends a trap to alert the management system, and responds accordingly (RDI upon AIS reception)
Continuity Check (CC) – used for checking service availability.
ACE-52 sends a CC cell periodically over a predefined VCC to verify that the link is functional
Loopback (LB) – used for fault localization. LB cells are sent with a destination address to be looped at any network element that was preassigned with loopback point address.
RAD's ACE-52 also loops back received LB cells.
Ethernet Capabilities of the RAD ACE-52
ACE-52 has up to two 10/100BaseT ports for the LAN/VLAN connectivity. The Ethernet frame size is up to 1594 bytes to allow special formats, including ISL and stacked VLANs (virtual LANs). The supported frame types are: untagged, priority-tagged and VLAN-tagged. VLAN-aware bridging is fully supported, including VLAN ID range (1 to 4094). Up to 128 VLANs can be defined. Four strict priority queues can be used at the Ethernet egress side for the traffic management. Traffic can be mapped to each of the queues according to VLAN priority. Thus, high priority traffic marked with appropriate VLAN priority is served first upon congestion on the Ethernet port.
ACE-52 provides L2 VPN services. Total traffic separation between customers is achieved by assigning VLAN IDs to virtual connections (VCs). Optionally, different priority levels can be
defined within each VPN by mapping VLAN priorities to different VCs with appropriate QoS parameters.
ACE-52 CES Capabilities
An optional Circuit Emulation Service (CES) port allows interconnecting PBXs, TDM multiplexers and video conferencing equipment over the ATM network.
The E1/T1 CES port supports structured (with or without CAS) and unstructured circuit emulation, as specified in AF-VTOA-0078.00.
The following timing modes are available for the CES port of the ACE-52:
Synchronous (derived from the ATM network)
Adaptive (for unstructured E1/T1 modes only), as defined in AF-VTOA-0078
Loopback (derived from the E1/T1 Rx clock).
SLA Differentiation with the ACE-52
Service providers can offer SLA differentiated services to generate
revenues from their existing infrastructure. In order to guarantee the SLA, it is important that the service providers have end-to-end control over the QoS.
By defining and monitoring traffic management parameters right from the customer’s premises, carriers gain the following advantages:
• Users do not over-utilize their allocated bandwidth
• Better statistical efficiency per link, while using the same backbone equipment
• Complete information on service performance. Access to this information can optionally be opened to users
• Proactive readiness for changes that need to be done on the network,
before services run into problems.
ACE-52 Alarm Forwarding
ACE-52 supports bidirectional alarm forwarding. An alarm detected at either the SDH/SONET or ATM level disables the unit's Ethernet port. Towards the ATM network, ACE-52 sends an SDH/SONET alarm or ATM OAM cells, to notify the remote end about the local Ethernet link disabling.
ACE-52 can be managed by up to 16 different managers simultaneously, using different ports and applications:
Locally, by connecting an ASCII terminal to the unit's RS-232 port
Remotely, over the ATM network using a dedicated VC
Over bridge, via the unit's Ethernet ports or bridge VCCs connection
Using RADview-EMS, RAD’s CORBA-based network managemen application via an IP-based connection. The RADview-EMS network management application monitors, configures, isolates faults and presents network statistics using a graphical, user-friendly display. This PC or Unix-based application alerts in real-time on service availability and faulty network conditions. Software upgrade and configuration files can be remotely downloaded or uploaded to ACE-52 via TFTP or XMODEM. Plug-and-Play The ACE-52 plug-and-play feature enables device installation without any pre-configuration or on-site setup to minimize truck-roll. When plugged into the network, ACE-52 automatically learns both its own (host) and the NMS (manager) IP addresses. A required configuration is then downloaded to the device from a remote site.
ACE-52 product data sheet (pdf)
Most commonly ordered RAD ACE-52 models: