nowMessenger! Messaging Protocols

One of the primary open standard internet messaging protocols is the Simple Network Paging Protocol or SNPP as defined in RFC 1861.

Based on our years of experience in the communications industry, we at nowMessenger! chose SNPP as the protocol for our messaging product.

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First, SNPP is a network protocol supporting direct connections between nowMessenger! and the messaging system. While modem access also provides direct access, and many of the same advantages, modems require local access numbers or toll charges and are notoriously difficult to configure for paging systems. An internet protocol like SNPP frees you to travel without worrying about losing your messaging capabilities.

Email, while quite reliable, is not always timely and there are no guarantees of timely delivery. Delivery will be delayed and messages queued whenever any gateway between the sender and recipient is down or heavily loaded. Since delivery has not actually failed (it is merely deferred) the sender is not notified. At least not for four hours in most cases. In most cases a wireless message needs to be a bit more timely.

A sender using an SNPP client, like nowMessenger!, is immediately notified of a network or addressing error, and can take alternative action.

Another advantage of SNPP clients is control over message content. The email or web gateways provided by paging and cell phone companies generally strip out email header information or otherwise restrict the size or content in an attempt to provide meaningful messages while optimizing transmission overhead. This may not meet your needs. With nowMessenger! you have total control over message content.

What about TAP?

Almost all paging systems provide TAP access and in some cases only TAP access is provided, but this is increasingly rare. The TAP protocol is dial-in, modem based and specifies 300 baud, Bell 103 compatible modem, though many systems support higher data rates.

The modem itself presents a few problems. First, the low data rate is not well supported by some modern modems and there is often a great deal of difficulty getting the modem to sync-up with the paging system modem. Very often the configuration for one provider is incompatible with that of another, so paging using multiple providers becomes difficult. Also, when a modem is used for TAP it cannot be used for other purposes and it must be reconfigured for other uses. This is inconvenient at best. SNPP allows sharing the modem service amongst other internet services or dispensing with the modem altogether if the computer is networked.

Reliable TAP access requires that the service provider install adequate phone lines and modems to support peak usage. SNPP requires only a single internet connection that is shared for all users.

Is there any information available on the Wireless Communication Transfer Protocol?

Information on the Wireless Communication Transfer Protocol (WCTP) is available on the web. The specification is available here.

Arch Wireless also provide a Developer's Guide to their implementation of WCTP.