All About the Whistle InterJet

Ethernet cables

Whistle shipped each InterJet with color-coded 10BASE-T cables, and its guides tell you which color to use for each job. This page collects what is known about them, so a missing cable can be replaced with a close match. It is drawn from Whistle's Administrator's Guides and setup card, and from one complete set that came with an InterJet 140 in the Netherlands, photographed by its owner, Tim de Brie.

• What came in the box
• Which cable goes where
• What the originals are made of
• Pinouts
• Making a close match
• The ISDN cable and the telephone cord
• Open questions

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What came in the box

Which cables a unit came with depends on its network card (Models). The 100, 120 and 130 have a four-port hub card; the 140 and 200 have a dual-Ethernet card, one Office port and one Perimeter port.

The guides for the InterJet 100/120 and 200 (WhistleWare 2.0) list the blue and orange cables for the hub-card models, and blue, orange and yellow for the 200, each with a telephone cord for the internal modem. The 140's setup card adds an ISDN cable.

Which cable goes where

A 10BASE-T link joins a port that transmits on pins 1 and 2 to one that receives on them. A computer's port and a hub's uplink port are wired one way (MDI); a hub's ordinary ports the other (MDI-X). A straight-through cable joins two ports wired differently, and a crossover cable joins two ports wired the same. The InterJet's two network cards are wired differently from each other, which is why the guides give different instructions for each:

The hub-card row comes from the 100/120 guide ("use the blue cable to connect it to a hub card port", and the orange crossover for a hub with no free uplink port) and from the WhistleWare 3 guide's troubleshooting table. The dual-Ethernet row comes from the 200 guide, which uses the orange cable "to connect a computer directly to either of the Ethernet ports".

Today most switches, and many computers, swap the pairs themselves (auto-MDI-X), so either cable usually links. The colors still matter for keeping a set original, and for an old hub or computer that does not. Each port on the dual-Ethernet card has two lights: LNK turns green when the link is good, and POL turns yellow "if the polarity of the cable is reversed", the sign of the two wires of one pair swapped at one end.

What the originals are made of

Read from the photo above. All three cables look alike apart from the color, so the yellow one's printing is probably typical of the set, but only the yellow one's is legible:

The Japanese labels on a set sold with a Dutch unit suggest Whistle used one bilingual label stock for every market rather than a Japanese-only one; the InterJet was sold in Japan (The InterJet in Japan). 周辺ネットワーク reads "peripheral network", the term the Models page's sources use for the Perimeter port.

Pinouts

Straight-through (blue and yellow). Through the blue cable's clear plug, the orange pair sits at one edge and the brown pair at the other. Brown is pins 7 and 8 in both wiring standards, so orange at the opposite edge is pins 1 and 2, which is T568B. The yellow plug looks the same, less clearly. That is a reading of a small photo, not a cable tester: treat T568B as likely, not established. Either standard works, provided both ends match.

Crossover (orange). The usual crossover is T568B at one end and T568A at the other, which exchanges the orange and green pairs: pins 1 and 2 at one end land on 3 and 6 at the other. The photo shows green wires in the orange cable's plugs but not their order, so whether the original is wired exactly this way, or crosses only the two pairs 10BASE-T uses, is not established. For an InterJet the two are equivalent.

Making a close match

• Cable: Category 5 or 5e unshielded twisted pair, four pairs, 24 AWG, with a solid-color jacket: blue, yellow and orange. The originals' exact shades are in the photo; jacket colors vary from maker to maker.
• Plugs: clear 8P8C plugs, crimped, with no boots. Buy plugs made for the conductor you have, solid or stranded; which the originals use is not known.
• Wiring: T568B at both ends of the blue and yellow; T568B at one end and T568A at the other of the orange. Check each with a cable tester before use.
• Labels: a white wrap-around label near the ends, "Office Network", "Perimeter Network" and "Crossover", in English and Japanese for a faithful copy.
• Length: a 2 to 3 m patch cable looks right, until someone measures an original.

Any working Cat 5 cable connects an InterJet, which runs at 10 Mb/s; this list matters only for a set that should look original.

The ISDN cable and the telephone cord

Neither is in the photo. The 100/120 and 200 guides list "a telephone cord that connects the InterJet to a telephone jack", for the internal modem. The 140's setup card shows a short light-gray "ISDN cable" with a modular plug at each end, for the internal ISDN card (ISDN). The Dutch card has RJ-45 jacks for the European S/T interface, which by standard uses a straight-through eight-position cable carrying its two pairs on pins 3-6 and 4-5. That it is wired this way is the standard, not a measurement of Whistle's cable.

Open questions

• How long is each cable?
• What do the blue and orange jackets say, and who holds UL file E135928?
• The pin order of each original, read with a tester or a sharp close-up of each plug: is the blue T568B, and how is the orange crossed?
• What is on the blue label's Japanese side, and is each label bilingual or is there one of each language per cable?
• Are the ISDN cable and the telephone cord also color-coded and labeled?

If you have an original cable, a length or a close-up of a plug would settle most of these; please contact me.