Is there any hardware VoIP PBX that allows external software to subscribe on its events, determine incoming caller IDs (including GSM numbers that have been gateway-ed) and perform outbound voice calls via API?
Thanks!
There are many PBX's which support Computer Telephony Integration (CTI).
The most common standards to support are CSTA and JTAPI - if you google 'PBX supporting JTAPI' for example you should see several examples in the first few pages of results.
Any PBX supporting these standards will most likely meet your needs.
It would be worth your while looking at Asterisk based PBX's also in case these met your needs and allowed more scope for further development/features if required in the future. Many firms make Asterisk PBX's - the following link provides a good list:
http://www.voip-info.org/wiki/view/Asterisk-based+commercial+PBX
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I have a couple of questions concerning BLE beacons:
1) Are beacons based on nRF51822 chip the best solution? Or are there any other chips better than nRF51822? I want to take up BLE beacon development and struggling to find the right hardware for these needs. As a novice developer I want the beacon to be as cheap as possible in order not to waste money in case of a failure.
2) Is it possible to buy pure Eddystone beacon (not iBeacon)? The reason for choosing Eddystone is that Eddystone is capable of broadcasting URLs that are essential for me.
The second question stems from my failed attempts to find a pure Eddystone beacon on Chinese electronics sites like alibaba.com or aliexpress.com where the only firmware available is iBeacon. But iBeacon is not an option because it can't broadcast URL the way Eddystone does.
Apart from the above questions It would be great if someone wrote a quick guide for taking up BLE development with Eddystone and covered basic topics like: chip to use, beacon model, best website to buy beacons at, etc.
Thanks in advance,
Pavel
1) I've worked with Estimote beacons and Chinese beacons from Amazon and in my opinion, they do not differ in terms of accuracy too much. Especially for prototyping, I'd buy cheaper ones to test if your use case can be satisfied with BLE beacons. If it is too inaccurate with Chinese beacons, chances are that it won't work with more expensive ones either.
2) Why do you need the URL broadcast? If the app is going to use the url, it would have to be connected to the internet. Therefore, you can just query the beacon's IDs to a web service to get back an URL and use that. Personally, I think this is a better approach as you can configure the web service from anywhere to change the url for beacons where as if you want to change the URL of the Eddystone, you have to go to the beacon to configure it.
The nRF51822 is a common implementation, is flexible, well understood and can be very inexpensive. Be aware though that development costs, add on circuitry for power and/or peripherals, and packaging can easily eclipse the Bluetooth chip when you get to production cost savings.
If you want to buy an off the shelf beacon, most models supporting Eddystone also support iBeacon, simply because supporting both adds no additional hardware cost. Newer Radius Networks and Estimote beacons all support both. And, yes, cheaper generic Chinese suppliers often have bulk manufactured inventory from before Eddystone existed at only support iBeacon.
I study the construction of mobile networks and began to study MVAS. But could not find a specific iinformation what protocols are used in the VAS or MVAS.
I understood that main protocol using SMS - it SMPP.
It would be great if someone made a list of the protocols used, or links where I could read more information about the protocols used.
There is such a list; it is published by 3GPP in specification TS 23.039.
3GPP (earlier ETSI) specified the GSM, UMTS and LTE systems, with standard protocols for most of the interfaces. They did not specify any standard protocol between Short Message Service Centres and external messaging servers though.
Instead, this was left open, and each SMSC developer specified their own protocol. An early and successful SMSC developer was an Irish company called Aldiscon, which was later taken over by Logica. They developed the Short Message Peer-to-Peer protocol (SMPP), and published it as an open standard, which is the reason why it's so widely used today.
What is the difference between SIP and H.323, I mean what are the salient features between them?
To start with ,
SIP is text based while H.323 is binary.
SIP is by IETF while H.323 by ITU.
SIP is basically request-response based like HTTP, while H.323 is not like that(is based on session).
What were the motivating factors which led to SIP's development?
How is one advantageous from other?
Both are relatively the same on the technical side - there are differences, but you can use both to run a VoIP service.
They both started at about the same time to develop, with H.323 gaining more traction in the beginning and SIP taking center stage in the past several years.
The main advantages of H.323 is the level of interoperability it provides in existing video conferencing equipment - something that can't be matched by SIP today (yet), and the fact that it holds most of the deployments of video conferencing in enterprises.
The main advantages of SIP is a larger ecosystem and dominance in voice calls and PBX systems. And the fact that it is viewed as the future of VoIP (at least to some extent).
I also wrote about it in the past in my company's blog: http://blog.radvision.com/voipsurvivor/2011/03/24/ask-an-expert-which-protocol-do-you-prefer-sip-or-h323/
H323 is familiar to telecommunications people. It reuses many concepts, terms and protocols from ISDN.
SIP is familiar to internet people. It's a lot like HTTP, re-uses all the response codes and standards like URI-s, uses the DNS well, etc.
I heard there is USSD Commands in Mobile.But i dont know what it is? i was googling two more sites.i did not understand it.Please anybody having knowledge about USSD Commands, share with me.
How it is useful when we using USSD Commands with our j2me midp 2.0 application development?
Please suggest me some useful URL's to get this properly.
Also, i would like to here about AT Commands too?
Thanks & Regards,
P.SARAVANAN
USSD is Unstructured Supplementary Service Data.
GSM standardizes on the syntax (i.e. message transport) of USSD but not on the semantics (i.e. what one can do with USSD is network-operator-specific).
USSD applies a request/response pattern. A user sends a USSD request which is processed by the network and eventually answered with an USSD reponse. In a nutshell, USSD allows an end user sending numerical commands. These commands are transported by protcol functionality within the SS7 signalling stack from the mobile device to the mobile network MSC (mobile switching center, the nework node controlling the mobile network). The network operator configures the MSC to handle specific USSD requests, typically to forward them to various other network elements. Among them are:
HLR (home location register, the user database) to switch on/off telephony services.
IN (intelligent network, the realtime billing platform, among others) voucher management system for prepaid top-up.
USSD gateway to branch out USSD messages to external systems.
These network elements then generate USSD responses which are transported back to the user.
Using USSD from J2ME is offered via:
Devices supporting JSR 120 (Wireless Messaging API). Consult manufacturers development documentation or device databases to check which devices are covered.
AT command (AT+CUSD) via serial interface emulation.
The user composes some message—usually rather cryptic—on the phone keyboard.
The phone sends it to the phone company network, where it is received by a computer dedicated to USSD.
The answer from this computer is sent back to the phone.
The answer could be seen on the phone screen, but it is usually with a very basic presentation.
The messages sent over USSD are not defined by any standardization body, so each network operator can implement whatever it finds suitable for its customers.
I'm doing a grad-school software engineering project and I'm looking for the protocol that governs communications between ATMs and bank networks.
I've been googling for quite a while now, and though I'm finding all sorts of interesting information about ATMs, I'm surprised to find that there seems to be no industry standard for high-level communications.
I'm not talking about 3DES or low-level transmission protocols, but something along the lines of an Interface Control Document; something that governs the sequence of events for various transactions: verify credentials, withdrawal, check balance, etc.
Any ideas? Does anything like this even exist?
I can't believe that after all this time the banks and ATM manufacturers are still just making this up as they go.
A shorter question: if I wanted to go into the ATM software manufacturing business, where would I start looking for standards?
Well, there are lots of interbank networks. I would guess that each of them communicate differently. The stickers on the ATM (Cirrus, STAR, Pulse, etc...) identify which network the machine participates in. I do believe, though, that the "structure" of the message is dictated by an ISO standard. Cirrus is a Mastercard owned network and PLUS is a Visa owned network... I'd scour their sites to see if they publish any API details.
Edit, by request:
Have a look at the following ISOs 15022, 20022, 9362 and 4217 -- http://en.wikipedia.org/wiki/Category:Financial_routing_standards
ISO 8583 is dominant.
Also, take a look at EMV.
The ATM to bank link can be proprietary or standard. It is only upstream where inter-organisation wire level interoperability is needed, that standards become always necessary.
ISO 15022 definitely doesn't cover ATM to bank. So far, it covers further upstream. And is now superseded by ISO 20022 - "originally named ISO 15022 2nd edition".
ISO 20022 covers the total scope of financial services, and acts as a super forum for ISO financial services protocols.
There are two basic protocols, ISO8563 and IFX (a financial XML subset) but many banks us protocols supplied by the vendor, because these include Device driver protocols that drive the ATM 'States', There is also a reporting protocol where the ATM reports its cash and usage statii.