Deploying Larscom's Edge Multi-service Access Concentrators with Orion 2000 allows an NSP to provide managed network services such as Transparent LAN Service (TLS), VPN, and ExtraNet.

An SNMP manager can connect to a local Orion 2000 via Ethernet 10Base-T, and to a remote Orion 2000 using an inband Telnet connection or external modem and SLIP. A terminal interface allows menu-driven management from ASCII terminals and PCs over local or remote RS232 connections, as well as via Telnet. A LarsView 2000 GUI is also available for graphical, point-and-click management.

Inverse Multiplexing for ATM

Inverse multiplexing for ATM (IMA) is a method specified by the ATM Forum for transporting ATM cells across a group of T1 or E1 lines. Developed as an alternative to DS3 or OC-3c/STM-1 ATM links, IMA provides fractional DS3/E3 bandwidth, with considerable cost savings as well as much wider availability. IMA also facilitates the interoperability of different vendors' equipment, increasing the options for network design and evolution.

Orion 2000 supports an OC-3c/STM-1 or DS3 UNI/NNI to a local ATM device, and a WAN channel comprised of up to eight inverse-multiplexed T1s or E1s. A common or independent transmit clock (CTC or ITC) can be specified, enabling non-synchronous or synchronous mode.

The rate differential between the DS3 or OC-3c UNI/NNI and the IMA channel makes buffering and traffic management supremely important. ATM traffic is by nature "bursty", so the ability to handle high-rate bursts can make up for a large disparity in bandwidth across an ATM path.

Orion 2000 provides an exceptionally large, 1 Megabyte buffer divided into four queues. These queues, which hold a total of 16,384 cells, allow users to tailor cell buffering to particular applications and traffic mixes. A 1,024-cell "reserved" queue is dedicated to signaling and ILMI cells, with discard occurring only on buffer overflow.

The other three queues--for CBR, VBR, and UBR (data) traffic--are independently configured by the user in 1,024-cell increments.

Discard conditions and thresholds for the CBR, VBR, and UBR queues are also user-specified. Thresholds for dropping cells and resuming buffer input can be set to any one-eighth increment of the buffer size. Cells can be discarded based on CLP marking, or Early Packet Discard (EPD) can be enabled for AAL5 frames.

To aid in congestion management, Orion 2000 supports Explicit Forward Congestion Indication (EFCI). Constant bit rate (CBR) traffic, such as real-time video, benefits from Orion 2000's very low cell delay variation.

Manageability of network equipment is a major concern in both private and service-provider networks--and a high level of manageability is built into Orion 2000. Management ports include two RS232 ports and one 10Base-T Ethernet port. In addition, a user-specified VPI/VCI can be defined as an end-to-end management link in the IMA channel. For flexibility, Orion 2000 includes common tools such as Telnet and TFTP.

Orion 2000 provides full SNMP and terminal interfaces, plus an optional LarsView 2000 Graphical User Interface (GUI). The SNMP Agent supports standard DS1/E1, DS3, and IMA MIBs, and Larscom extensions.

The easy-to-use terminal interface features menus and pop-up windows. It supports local and remote connections, including automatic dialout, and provides access to all of Orion 2000's extensive configuration, performance management, and diagnostic functions.

Orion 2000 monitors unit, cell, T1/E1, and DS3/OC-3c/STM-1 parameters full-time, giving you a detailed picture of performance at all levels. User-selected alarms notify you of critical problems, while numerous 15-minute and 24-hour registers provide the historical data you need for trouble analysis, documentation, and trending. To aid in problem isolation, Orion 2000 implements a range of T1/E1, UNI/NNI, and cell loopbacks--as well as the IMA pattern sync test.