Multitech MultiModem iSMS SF100-G Instrukcja Użytkownika Pobierz pdf (Strona 2)

article describes the system I am using, which is the MultiTech

Systems MultiModem iSMS Intelligent SMS server (Figure 1)

in combination with a public domain Perl script running on

a Linux-based Nagios server.

I selected this hardware and software combination for

the following reasons:

I Another company had done all the required work to

integrate the iSMS device with Nagios, clearly documented

the process and made this freely available on the Web,

including the Perl script described in this article.

I A major feature of the Perl script is the ability to “ACK”

or acknowledge a Nagios alert. This means you don’t have

to have any kind of IP connection to your Nagios server to

perform acknowledgements. The ability to acknowledge alerts

is helpful when you are off the IP network, as it stops any

future alerts and can prevent the alerts from going to others

if you have configured Nagios to do this. The script also can

force a service or host back to an “OK” state if desired.

I The iSMS device is a standalone “appliance” and does not

depend on any infrastructure other than a (local) Ethernet

connection, GSM cellular service and electrical power. Most

other products in this area are similar to traditional analog

modems in that they have serial connections hard-wired to

a specific host. As the iSMS is connected via Ethernet, it can

be accessed and shared by multiple hosts. The particular

model I used has a single GSM modem, but four- or eight-

modem versions are also available.

I Other Nagios users are using conventional mobile phone

handsets in this role, but I feel that consumer-level power

supplies and some kind of jury-rigged mounting of a phone

in a machine room would undermine the reliability I want.

The iSMS has a robust metal case and can be attached

securely to a rack. The power plug is threaded to the

chassis to prevent accidental unplugging.

I The iSMS has a Web-based administration interface and

supports multiple methods of communication, including a

“Telnet” interface to connect directly to the GSM modem

for use of “AT” commands and multiple APIs. These include

both TCP and HTTP APIs for sending and receiving SMS

messages or querying the status of queued messages.

Certainly, you could use Web-based or e-mail-based

tools to create a similar alerting functionality, but SMS

is somewhat unique in that it does not require an IP

connection and is generally available wherever a modern

cellular infrastructure exists.

As you can see in Figure 1, the iSMS is packaged in a

sturdy metal enclosure. I used large plastic wire ties to mount

the iSMS to a horizontal rack post, but it also can be mounted

with screws. The antenna is visible on the top, and there is

a little hatch on the bottom where the Subscriber Identity

Module (SIM) card is plugged in.

Ordering the iSMS

The product is generally available, and I simply used a price

comparison site to find the cheapest one, as I didn’t feel I

needed support from the vendor. MultiTech made several

changes to its product while I was in the midst of writing

this article. These changes included renaming the product,

updating the firmware version and lowering the price. The

iSMS previously was named SMSFinder, and you will see this

reflected in the name of the Perl script and in other places.

The firmware update required some changes in the Perl code.

The original product was priced around $700, but it’s now

available in the $400 range. This article describes the more

recent version of the iSMS and Perl script.

Ordering SMS Service

I did not shop around between the different carriers for SMS

service, as my company already had a corporate account with

AT&T. I initially tried to walk into an AT&T retail store to buy

service for the iSMS, but I was unable to purchase a service

package that did not include voice. I ended up doing all the

ordering and setup over the phone with AT&T corporate.

I was able to get the SIM card at the retail store, which

saved me from having to wait for the card to be mailed to

my location. AT&T calls its text-only SMS service telemetry.

It may make the ordering process easier if you use this

terminology with your carrier.

Once you reach the correct ordering department, all you

should need to do is read them two numbers: the first identifies

the iSMS, and the second identifies the SIM card. The number

for the iSMS is the International Mobile Equipment Identity

(IMEI) number printed on the iSMS chassis label. The second

number, the Integrated Circuit Card ID (ICC-ID) is printed on

the SIM card. Once I had communicated these numbers to

the carrier, I was able to establish the service and send a test

message within a few minutes. Make sure you make note of

the subscriber number given to you, as this will be the source

of SMS alerts and the destination for your “ACK” and

“OK” responses. It is handy to associate a contact name

with this number for caller-ID purposes on your mobile

phone (for example, “Nagios”). With the service I purchased,

the one-time setup fee was $18, and the monthly charge

is about $9, depending on usage.

www.linuxjournal.com march 2010

| 3

To read more Linux Journal or start your subscription, please visit http://www.linuxjournal.com.

Figure 1. MultiTech Systems MultiModem iSMS Intelligent SMS Server

1 2 3 4 5

Komentarze do niniejszej Instrukcji

Brak uwag

Multitech MultiModem iSMS SF100-G Instrukcja Użytkownika Strona 2

Komentarze do niniejszej Instrukcji

Powiązane produkty i podręczniki dla Serwery Multitech MultiModem iSMS SF100-G