SPS-4 Multi-protocol Packet Switch from RAD
SPS-4 is a 3-link multiprotocol packet switch, providing multiprotocol connection between the enterprise headquarters and remote branches (see Figure 1). The RAD SPS-4 allows the X.25 and Frame Relay protocols to run over an IP backbone, while retaining the functionality of the SPS family products.
Other features include:
Support for the Legacy over IP architecture
Asynchronous backup channel for GPRS packet streams
ISDN interface.
SPS-4 w/FRAME RELAY:
SPS-4 provides access and switching to public or private Frame Relay networks, and consolidates asynchronous, HDLC, IP and X.25 traffic over the Frame Relay network. As a Frame Relay switch, SPS-4 integrates DLCIs from several sources into a single port. The RAD SPS-4 also supports BECN/FECN signaling for congestion avoidance. A unique funneling mechanism adjusts feeder throughput to CIR levels. The Frame Relay multicasting feature (complies with FRF-7) enables multicasting frames from one DLCI onto several DLCIs. This feature supports one-way, two-way and broadcast communication options.
LMI and ANSI PVC management protocols are supported in compliance with ANSI T1.606, T1.618, T1.617 Annex D, and ITU Rec. Q.922, Annex A. SPS-4 supports CLLM management protocol and complies with ITU REC Q.933, Annex A.
SPS-4 w/ X.25
X.25-configured links support permanent virtual circuits (PVCs) and switched virtual circuits (SVCs). Link packet size is up to 4096 bytes. SPS-4 handles both mandatory and additional ITU X.25 facilities. Dial-up X.25 links are supported via a dial-up modem, controlled by a DTR signal or V.25 bis commands.
X.25 multicasting is supported.
SPS-4 w/ X.32
The RAD SPS-4 supports the X.32 protocol for a dial-up X.25 link. This enables users to access an X.25 network remotely via a dial-up modem with X.32, or to use the backup dial-up link for an X.25 or Frame Relay network.
SPS-4 w/ ISDN
SPS-4 allows PPP/FR/X.25 data to be transmitted over ISDN media. The ISDN data rate is up to 192 kbps.
SPS-4 HDLC TRANSPARENT ACCESS
Each port can be programmed to operate in transparent HDLC mode for connecting bridges, routers and other HDLC communication devices over X.25 or Frame Relay networks. The HDLC protocol is encapsulated over X.25 or Frame Relay, providing end-to-end transparent operation.
SPS-4 ASYNCHRONOUS ACCESS
All asynchronous channels function according to the X.3, X.28 and X.29 profiles, at traffic speeds of up to 115.2 kbps. Asynchronous traffic can be
packetized directly over the Frame Relay network, or packetized over the X.25 network. All channels are configured and monitored by the SPS-4 management agent. Each SPS-4 port can be configured to SLIP or PPP mode, operating at data rates of up to 115.2 kbps. IP PAD facilities allow
straightforward migration of terminal/server applications to an IP environment, while improving its durability at the same time.
SPS-4 IP ROUTING
The RAD SPS-4 routes IP datagrams over Ethernet, PPP or SLIP links and over Frame Relay networks (according to RFC 1490), or over X.25 networks (according to RFC 1356).
SPS-4 supports RIP1, RIP2 and triggered acknowledgment RIP messages (according to RFC 1058, 1723 and 1724). The RIP support enables trouble-free
IP connection while minimizing IP user configuration. The triggered RIP enables reduction of the overhead associated with the RIP mechanism, by minimizing the number of periodic messages sent.
SPS-4 MANAGEMENT CAPABILITIES
The RAD SPS-4 can be managed using different ports and applications:
Local out-of-band management via an ASCII terminal connected to the RS-232 port
Remote inband management using RADview-Lite, RAD's SNMP-based management system.
The SNMP agent can be programmed to periodically send statistics and status reports to a maximum of five management stations.
A management station can be connected directly to SPS-4 using LAN, PPP or SLIP.
The SPS-4 SNMP agents recognize both private and standard MIBs, including MIB II with RFC 1213, RFC 1381 and RFC 1382 for X.25, and RFC 1315 for Frame Relay.
SPS-4 BACKUP AND RECOVERY
SPS-4 supports stream backup over PSTN, ISDN and GPRS networks.
Frame Relay, X.25 and PPP can be transmitted over the ISDN media (see Figure 2).
After a network recovery, SPS-4 automatically synchronizes itself with the main facility link.
SPS-4 Multi-protocol Packet Switch product
data sheet (pdf)
