The Perle IOLink 520 is a multi-protocol router designed to fit into LANs and WANs, as well as provide VPN capabilities. The design of the IOLink 520 allows a number of different modules to be placed inside the chassis, altering the connectivity options available for administrators. A set of different modules are available, including standard 10/100Mbps Ethernet LANs, WAN, ISDN BRI, and a CSU/DSU unit. The physical dimensions of the IOLink 520 limit the combinations of modules available, but in most situations three different cards can be housed (for example, one LAN and two WAN, or one LAN and two ISDN, etc.). This configurability of the IOLink 520 is attractive in that it allows future expansion or modification of the basic unit without having to discard existing hardware, or purchase new units to provide simple expansion.

The IOLink 520 is a long, half-normal width unit measuring two inches high, sixteen inches deep, and ten inches wide. Although not intended for rack mounting, two IOLink 520 could be accommodated in a rack-mount tray without problem. The light plastic case has four status LEDs on the front panel, arranged in a nice cross pattern (a welcome change for a row of LEDs!). Our test IOLink 520 was provided by Perle equipped with one of each of the three types of modules: an ISDN BRI, a WAN, and a LAN module. All three sit side-by-side inside the chassis with external faceplates holding connectors. To the right of the back panel is a power cord. The ISDN BRI module has a single ISDN jack; the WAN module has a V.35 RS232-25 port, and the LAN module has two RJ45 ports and an RS232-25 console connector.

The 10/100Mbps Ethernet module supports concurrent IP and IPX routing, transparent bridging, L25 data compression, and NAT/NAPT/Reverse NAPT protocols. The ISDN module has a 128kbps throughput with adaptation to a single 56kbps (V.110). The IOLink 520 supports the usual alphabet soup of protocols, including TCP/IP, IPX/SPX, RIP and RIP2, SAP, ARP and proxy ARP, and ICMP. The WAN protocols supported by the IOLink 520 are PPP and PPP-ML, Frame Relay, and BACP. The router supports standard Ethernet with transparent MAC layer bridging, as well as 802.1D STP. Security features use PAP, CHAP, and the NetSafe Firewall system. The entire unit can be SNMP controlled.

The documentation accompanying the IOLink 520 is quite large, with both a User/System Administration guide and a reference manual. Both documents are well written, and should provide all the information administrators need.

To test the Perle IOLink 520 we installed our test unit as a link between the Internet (through the ISDN interface), and two network segments running 10 and 100Mbps Ethernet respectively. Since we had only a single IOLink 520 we couldn’t test the WAN-WAN connectivity of the Perle system itself but we did bridge the IOLink 520 to other WAN routers with complete success. The IOLink 520 was used on our internal networks for almost a week, supporting both TCP/IP and IPX/SPX on the internal network, and PPP-ML over the ISDN connection. The IOLink 520 was managed by an SNMP Windows 2000 Server unit with no problems. The installation and configuration of the IOLink 520 was simple, taking only five minutes. It really is a plug-and-ignore solution to LAN and WAN connectivity. We used a console connection to configure the IOLink 520 from a Linux box.

Gauging the speed throughput of the IOLink 520 was difficult, as we couldn’t get sustained high-end limits. A datascope on the line indicated it easily handled all the 100Mbps Ethernet traffic, which peaked at 62.3Mbps over fiber links. When Frame Relay was used across the WAN port, we measured speeds approaching 1.7Mbps, close to the theoretical 2.048Mbps supported by Frame Relay on leased lines. The IOLink 520 supports 128 DLCIs in Frame Relay applications.

The VPN features of the IOLink 520 provide IPSec (IP Security) with IKE (Internet Key Exchange) and DES encryption native in the unit. The standard authentication schemes of PAP and CHAP are used. We didn’t spend much time looking at the VPN features of the IOLink 520 as they are industry-standard protocols and should cause no problems for anyone using them.

The Perle IOLink 520 stood out by, paradoxically, not standing out. Throughout our test period we didn’t have any hiccups or problems with the IOLink 520 at all. It simply functioned perfectly, quickly, and transparently in our networks. Even when we tried our usual tricks to try and confuse or crash the router, the IOLink 520 continued quite happily. If you need a configurable, multi-protocol router and WAN/ISDN interface, the Perle IOLink 520 will certainly be a must-see. For connection of two or more small office locations, this may be one of the easier approaches available.

IOLink 520
Perle Systems Ltd
60 Renfrew Drive
Ontario L3R 0E1

700 Commerce Drive
5th Floor
Oak Brook
IL 60523
630-288-2651 fax

Summary: The IOLink 520 provides a modular approach to LAN/WAN and ISNM connectivity with built in VPN capabilities. An impressive (and easy to work with) unit.