ISPPlanet • Stallion ePipe - page 2

Under the hood

The 2148 is a brick-sized access router, just large enough to house 12 RJ-45 jacks, representing an integrated 8-port 10BaseT hub and 4 serial ports. For customers who need more analog or ISDN bandwidth, consider the 2188 featuring 8 serial ports, or the 2181 with 8 serial ports and one 10/100 Ethernet port. The dual 10/100 Ethernet 2202 provides Internet access using PPPoE and external DSL or cable modems. Finally, the ePipe 2242 provides both serial and dual-Ethernet ports for broadband access with dial backup.

We used two independent test topologies to put the ePipe 2148 through its paces. To evaluate I2B, we connected a single ePipe to the Internet with three analog modems. We used different modem brands to assess compatibility—Boca, USR, and MultiTech). None of our modems were among the chosen few—Banksia, Maestro, Netcom, USR 56K—with built-in ePipe scripts. We had no trouble using the ePipe's generic scripts, but could have created our own custom scripts as well.

To evaluate E2B, we deployed a pair of ePipe 2148s in two buildings. Each ePipe ran E2B over the Internet using a pair of USR Courier v.Everything modems. So that our traffic would encounter diverse routing, we placed calls through three different ISPs. The raw intersite bandwidth in this configuration was certainly at the low end of what's possible. Bonding four ADSL or cable modem connections should, in theory, yield multi-megabit capacity. But, according to Merenda, finding a testbed to demonstrate this has been a challenge.

Installation and setup
As WAN access routers go, the ePipe is relatively easy to configure. Just connect modems with supplied cables, plug a PC into the integrated hub, and insert the supplied CD into the PC. A discovery program (below) Address Resolution Protocols (ARP) to find the ePipe and assign it an inside IP address.

(Click image to enlarge view)

Thereafter, the ePipe can be managed with any web browser. The GUI is clean and simple, offering wizard-based setup and keyed feature activation. We found the telnet-accessible CLI very usable, though somewhat cryptic. The GUI and CLI are password-authenticated, and filters can be used to restrict inside/outside admin access, like blocking incoming telnet attempts. Because the GUI is not SSL-encrypted, ISPs using the ePipe in a managed service may wish to encrypt administrative traffic with PPTP or IPsec (See SRA and SSV examples).

To represent more complex bonding scenarios, SIA is configured with a hierarchy of ports, links, and connection bundles. In our case, we started by creating links for v.90 dial-up access. A 20-step wizard guides the first-time user through port, modem type, telephone number, and ISP account settings. When using identical modems and a login authorized for multiple active connections, links can be associated with several ports, using the first available.

Next, we combined links into connection bundles. Each named bundle contains one or more links, a set of filters, and a set of NAT rules (further described below).

After completing this wizard, results are visible from the Advanced Summary page. This summary offers at-a-glance status and control. Bundles and links are easily enabled/disabled by clicking the on/off icon, and parameters are readily viewed by clicking through to the affected bundle, link, or port.

Dynamic bandwidth, configurable control
Stallion's ePipe is a dial-on-demand router—lines are activated as needed, based on configured parameters. Line bandwidth can be configured manually or determined automatically, based on port or CONNECT speed—if accurately reported by the modem. Or, any link can be enabled/disabled statically.

Dynamic activation is controlled by bundle bandwidth. Upper thresholds determine the sustained utilization which causes a call to be added—lower thresholds determine the inactivity level at which to drop a call. In the example shown here, another call is placed if any link exceeds 60 percent utilization for 30 seconds.

If any link transfers less than 20 percent of its capacity for 60 seconds, that call is dropped. To prevent hysteresis, whenever bandwidth changes, the ePipe waits for a stabilize period before making further decisions. It is easy to put a bundle into place with basic settings, but most users will optimize these parameters over time. We experimented with dynamic links, but ran performance tests with static links to ensure consistent bandwidth.

Filters determine what traffic can enter the WAN and how it affects link status. Most ISPs will have no trouble understanding ePipe filter syntax, but customers might. For that reason, ePipe includes a filter wizard to select a traffic type, an action—reject, discard, allow in/out—and choose how this kind of traffic contributes to bundle up-time. An example of bundle up-time would be to keep a link up for at least 60 seconds after sending or receiving HTTP.

Again, most users will define a simple filter to get started, and continue to refine the filters through trial and error. We found it necessary to use detailed logging (enabled from the CLI) to identify RIP broadcasts that were keeping our link active. A FAQ on this would be a nice addition. Time-based filters, like activate link only from 9 am to 5 pm, were not in the firmware we tested, but are planned for the next release.

Like most access routers, the ePipe supports WAN address sharing with network address translation (NAT). In addition, NAT rules can be defined for any bundle to enable outside access to inside hosts. This example shows how we forwarded web traffic to one inside server and FTP traffic to another.

These dial-on-demand and firewall features are nicely configurable for an inexpensive access router. However, the ePipe is more complex to manage than entry-level Internet appliances that lack this detail.