RAD SPS-3S Multiprotocol Packet Switches

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RAD SPS-3S Multiprotocol Packet Switches


  • SPS-3S is a 3-port FRAD/PAD and multiprotocol packet switch intended for the remote branch office. The device supports aggregated data rate of up to 2 Mbps.
  • Typical applications include: access for the small office in a multi-protocol environment (see Figure 1), protocol converter and consolidation of LAN traffic for transmission over Frame Relay, X.25 or ISDN networks (see Figure 2).


  • SPS-3S provides access and switching to public or private Frame Relay networks.
  • SPS-3S consolidates Async, HDLC, IP and X.25 over the Frame Relay cloud.
  • As a Frame Relay switch, the unit can integrate DLCIs from several sources into a single port. It can also support BECN/FECN signaling for congestion avoidance.
  • A unique funneling mechanism adjusts feeder throughput to CIR levels.
  • For each DLCI, an optional backup Frame Relay link is available.
  • The Frame Relay multicasting feature (complies with FRF-7), enables multicasting frames from one DLCI onto several DLCIs. The 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-3S supports CLLM management protocol and complies with ITU REC Q.933, Annex A.


  • X.25-configured links support permanent virtual circuits (PVCs) and switched virtual circuits (SVCs). Link packet size is up to 4096 bytes.
  • SPS-3S supports both mandatory and additional ITU X.2 facilities.
  • Dial-up X.25 links are supported via a dial-up modem controlled by a DTR signal or V.25 bis commands.
  • SPS-3S supports X.25 multicasting.


  • SPS-3S supports 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.


  • Each port can be programmed to operate with transparent HDLC 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.


  • All async channels can act according to X.3, X.28 and X.29 profiles at traffic speeds of up to 115.2 kbps. Async traffic can be packetized directly over a Frame Relay network, or packetized over an X.25 network. All channels are configured and monitored by the management agent of SPS-3S.
  • Each one of the SPS-3S ports can be configured to SLIP or PPP modes, operating at data rates of up to 115.2 kbps.
  • IP PAD facilities allow easy migration of terminal / server applications to an IP environment, at the same time improving its durability.


  • IP datagrams can be routed over Ethernet, PPP or SLIP links and over Frame Relay networks (according to RFC 1490) or over an X.25 network (according to RFC 1356).


  • The Ethernet interface enables bridging and/or routing of LAN packets over a Frame Relay network (according to RFC 1490) and over an X.25 network (according to RFC 1356).
  • SPS-3S supports RIP1, RIP2 and triggered acknowledgment RIP messages (according to RFC 1058, 1723 and 1724). The RIP support enables easy 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.
  • Static IP routing is supported. IP packets are routed to destination via SLIP, PPP, LAN (Ethernet), X.25 or Frame Relay link, according to the IP address.


  • PPP / Frame Relay / X.25 can be transmitted over the ISDN media.
  • ISDN support includes up to 128 kbps (Bundle two B channels).


  • SPS-3S contains an SNMP agent, which enables remote configuration, collection of statistics / status reports, and diagnostics. The management agent can be programmed to periodically send statistics and status reports to a maximum of five management stations.
  • Configuration, monitoring and controlling of all network resources can be performed from a RADview-PC or RADview-HPOV/UNIX management station.
  • A management station can be connected directly to SPS-3S, using LAN, PPP or SLIP.
  • SPS-3S SNMP agent supports private and standard MIBs, including MIB II with RFC 1213, RFC 1381 and RFC 1382 for X.25, and RFC 1315 for Frame Relay.


  • Enhanced backup facilities include PSTN/ISDN support.
  • Frame Relay, X.25 and PPP can be transmitted over the ISDN media.
  • SPS-3 features an automatic return to the main link facility after a network recovery.


  • 3-port FRAD/PAD and multiprotocol packet switch
  • Protocols supported: Frame Relay, X.25, IP, HDLC, SLIP, PPP, ML-PPP and Async
  • IP support:
    • RIP1, RIP2 and static routing
    • Standard IP encapsulation over Frame Relay (RFC 1490), or X.25 (RFC 1356) networks
  • Telnet client / server to support terminal / server applications
  • Standard bridging
  • SNMP management using RADview PC / UNIX platforms
  • Optional built-in Ethernet port, allowing easy integration of LAN segments
  • Optional support for ISDN: Frame Relay / X.25 / PPP / ML-PPP can be transmitted over the ISDN media
  • FLASH memory for software upgrade

3-port Multiprotocol FRAD/Switch

$ Specify optional DC power supply:
24 for for 24 VDC
48 for 48 VDC
# Specify link 1 interface:
V24 for V.24 interface
V35 for V.35 interface
X21 for X.21 interface
530 for RS-530 interface
V36 for V.36/RS-499 interface
DDS for integral CSU/DSU
IBE for ISDN BRI `S' interface
IBU for ISDN BRI `U' interface
UTP for integral 10BaseT interface
BNC for integral 10Base2 interface
* Specify link 2 and 3 interface:
V24 for V.24 interface
V35 for V.35 interface
X21 for X.21 interface
530 for RS-530 interface
V36 for V.36/RS-449 interface

Note: All V.35 V.36 and X.21 interfaces include an adapter cable.






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