There are many companies which provides sim card hosting services for receiving sms, I wanna how is this possible (at the core level)? do they use any kinda protocol or any custom devices for forwarding text messages to there servers.
This depends on the type of SIM card hosting being offered, if it is Virtual SIM card hosting (VSIM) such as this https://www.world-text.com/services/virtual-sim-hosting/ then this is only achievable were the provider has a direct connection to a mobile network over SS7. This requires very specialist knowledge, software and hardware, but is a very reliable and fast option.
If however they are offering GSM modem based SIM card hosting such as this http://world-text.com/services/sim-hosting/ then this utilises GSM modems which are normally hosted in a data centre and communicated with over IP, with messages returned to the providers SMSC. This method is slower, and is of course reliant on a local cell tower signal to work.
Related
How can I establish a session-based M2M connection with gammu? I'm using hardware module SIM800L and a 4G SIM card. I can do USSD and SMS with gammu, but USSD can only be used to communicate with the operator network, not other SIM card, and SMS is costly since even for 10 chars we must pay the price of an SMS. So, I'm looking for a session-based connection where I pay for the traffic.
If gammu does not allow this, is there an alternative?
Thanks.
Gammu does not allow for more than USSD and SMS.
For a GPRS connection, use wvdial.
What software/hardware do the SMS centers use to make the following possible:
An SMS is received to a number. The SMS is routed to one of X machines (Mac/PC). An operator responds to the sender.
It seems that a GSM modem is needed? However, I have trouble understanding the architecture.
Is there any plug-and-play solution? Are there any specific frameworks/languages/tools for building such a system? How do you route incoming messages to machines? How do you queue outgoing text messages?
For getting SMS there are at least 2 types of numbers exist: real (simcards) and virtual (VLN).
Real numbers:
-simcards you need to own and to insert into devices called gsm-gateways or gsm-modems, gsm-modem pools etc. These devices are like collection of many mobile phones, they will collect and/or keep/forward all incoming SMS (to some DB, to server/script etc.)
-to make lot of users manage SMS you need some tool. Most common - webserver with appropriate GUI software. Webserver collects all SMS into DB (by downloading them from gsm-gateways via protocols like SMPP or HTTP, or by geting as HTTP Requests from devices). Via some WEB-GUI you can make messages available to your operators for replying.
Virtual numbers (VLN) (provided by most SMS operators):
-no need for hardware. Just contract operator for numbers, then connect via HTTP API or some protocol like SMPP for collecting inbound SMS on these numbers, or get them on your server as HTTP Requests from operator's server.
-WEB-GUI the same as for real numbers
So basically the flow is:
for Real numbers: SMS Origination from phone -> GSM-operator (Vodaf... etc) -> SIM-Card (Vodaf...) in GSM-gateway -> GSM-Gateway API -> Your Web-GUI
for Virtual numbers: SMS Origination from phone -> GSM-operator (Vodaf... etc) -> SMS Service provider (Clicat... etc.) API -> Your Web-GUI
There are some software titles free and paid available for each task.
Any organisation with a large amount of traffic will most likely use a connection to an opertors SMSC (SMS Message Centre in an operators network) via an IP interface and the SMPP protocol.
The SMPP protocol is an open standard designed to bridge the IP web world to the CCITT No.7 messaging world in the telcos, and allow web services be built to send an receive SMS's.
There are also providers who provide aggregation services for SMS - some are independent and some are 'preferred partners' of an operator (e.g. http://developer.att.com/technical-library/app-certification-policies/working-with-aggregators)
I want to know how can I build my own Sms service provider?
In another say; What is needed to have a system to inject sms messages to the mobile network systems freely or is it possible at all?
with VoIP server we can do voice and video and text messaging through internet; but what about from internet to the land line or mobile network?
How Skype, smartvoip, etc. do this?
Please give me a direction that I could go through.
You need some sort of interface to the Mobile network to make this work. Your choices include:
build a system with a GSM/UMTS card or phone which you control to send SMS messages into the network. This will need a valid SIM and contract (and the small print may say that you are not allowed to use it to provide an IP to SMS service to others). If you google 'Asterix SMS Gateway' you can find several open source examples. You could also look at http://www.kannel.org/overview.shtml, although I am not sure how actively this is being maintained these days.
Build a front end for your SMS service and use an existing back end SMS service in whatever your target market is - i.e. connect directly to your local operators SMSC, most likely using SMPP protocol. This assumes the operator provides this service in your target network/market.
Use an SMS aggregator service such as MBlox or Clickatell
There is a hardware system that uses a gsm shield to have an access to the internet. The system should be reliable and all ddos attack vectors are taken into account.
We afraid of sms ddos attack, that can be realized via sending too much sms messages (or especially malformed sms/invisible sms/binary sms). The question is does the receiving of sms hampers the traffic sending for gsm shield/modem? What happens with traffic sending at the moment when the sms is received? How many time the shield /modem is out of sending traffic service per each sms?
SMSs are usually transmitted over a control channel, like the SDCCH (Stand-alone Dedicated Control Channel) or the FACCH (Fast Associated Control Channel). These are the same channels which are used to initiate and hold a call. It is possible to receive SMS while a call is in progress by temporarily reallocating part of the data channel to a control channel (e.g. SDCCH) and using this bandwidth to transmitt/receive an SMS.
If DDOS is possible, I think, depends more on the bandwidth allocation policy of the mobile network operator.
Of course, since the free air used for signal transmission is a shared medium for everyone in a cell, it is always possible to generate heavy load by gathering a group of people all sending SMS and making phone calls at the same time in close proximity of e.g. your GSM shield, effectively staging a DDOS attack if it's done on purpose.
I am stuck in the midst of a project. The project requires that a desktop pc must receive an sms sent from a mobile phone. How can I accomplish this? Please help.
You can connect a GSM Modem like this one to the serial port. It acts like a mobile phone with its own SIM card. I'm sure there are other products for USB.
On the software side, you can check for SMS messages by talking with AT commands to the device. I've done that in Perl and in .NET "manually", but maybe there are some out-of-the-box solutions.
i know (and have used) 2 ways to do this.
The quick, dirty and hacky way is to buy a mobile phone and connect it to your PC with a serial cable, then use old fashioned AT commands to control the phone (including listening for new SMS messages).
Many older Nokias support this, though it's not hugely well documented - this is about the best resource I found: http://wiki.forum.nokia.com/index.php/AT_Commands.
There are many exciting ways this can fail - you have to keep the phone charged, and in a data centre, reception is often pretty poor.
The alternative is to talk to a mobile aggregator (Google for likely candidates in your area). These are companies that can set up SMS short codes, and have APIs for forwarding the messages to you; APIs vary between the providers. This is usually fairly expensive - shortcodes cost money, sending and receiving SMS messages costs money, and the aggregator may not have deals with countries you care about. Caveat emptor, and all that.
You would also need a library to send/receive the AT commands to and from the modem.
See http://www.codeproject.com/KB/vb/phonesmsrecv.aspx
This software can help you. It uses a GSM/3G modem attached to a PC. It can store incoming SMS messages in a database, save to files, forward them to a webserver, in real-time.
(A 3g/gsm modem has a SIM card and therefore has its own phone number to which sms messages can be sent)