I'm not sure if this is a stackoverflow question but,
To my understanding SIP Trunking is a VOIP protocol that
allows a person to call through a phoneline and than some datacenter will convert that into an internet call.
My question is, is it the only protocol? Are there other protocols that can be used for VOIP?
There exists a technology known as PRI. Both PRI (Primary rate interface)and SIP(Session Initiating Protocol) are used connect your business to Public PSTN networks.
PRI and SIP both needs a physical connection to PSTN network. The problem is more conventional in such way that it uses Circuit switched model and only support Voice messages.
Sip uses existing data channel and uses packet switched model to communication, we can send voice and sometimes FAX messages through SIP.
In business point of view, SIP is more scalable and profitable compared to PRI service(Even though a PRI offers more Quality Voice service).
Traditionally fixed line VS SIP configuration
Related
What is the difference between broadcaster and beacons? From what I understand a broadcaster is a role in the GAP which sends out advertisements which contain data and are unable to make connections. They usually work in tandem with observers. Beacons do the same thing so what is the difference?
It's a bit like asking what is the difference between a HTTP server and a Web Server. A Web Server is a computer that stores web sites which it makes available over the internet, while a HTTP server is a piece of software that implements the server part of the HTTP protocol.
A Broadcaster is a role in the GAP specification which simply sends out advertisements, just as you say. It's defined in section 2.2.2.1 of the GAP chapter (in the Core v5.3 specification). Observer is the opposite role.
The word "beacon" is not present anywhere in the >3000 pages long Bluetooth Core specification. It's a term made up by industry, presumably because it works good in marketing or is generally a good name to describe this type of product. Beacons typically send out their positions using BLE advertisements for location tracking purposes but can also be connectable for various purposes.
Broadcaster is just a technical term and Broadcasters do not have a specific product purpose, which beacons on the other hand usually have. For example, iBeacon is a product which uses a specific data format containing identifiers. This product then uses the Broadcaster role and sends this data over BLE.
There is no difference. While broadcaster is a technical term used in the Bluetooth specification, beacon is simply the name of a class of products based on Bluetooth LE technology.
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.
Could somebody tell me what does mean 'DCS' in IP telephony communication standards?
I have looked at the internet and found that DCS is a distributed control system, but I think it's not relevant information when we talk about IP telephony communication standards.
A DCS is probably a Digital Cross Connect System in the context you have seen it, although it also seems to be a popular set of letters to include in product names, so check that it is not simply this you are seeing.
A digital cross connect is a 'box' or device that allows you switch between digital circuits - e.g. connect an incoming digital 'trunk' to an outgoing digital 'trunk' or phone 'line'.
You are correct that 'pure' IP telephony does not generally have to use cross connects as it is packet switched rather than circuit switched, but in the real world most IP telephony systems have to interface with or connect to older digital circuit networks and equipment.
For this reason you may see devices which act as a gateway between IP telephony networks and circuit switched digital networks - these boxes are often called Media Gateways.
See more about DSC at: http://en.wikipedia.org/wiki/Digital_cross_connect_system
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 need to implement a simple application to send short notify messages on gsm phone display via a GSM modem.
I know that I can use the gsm USSD protocol to send messages instead of sms in order to speed up the delivery.
Where I can find a detailed reference on the available USSD messages?
Where I can find examples or sample applications?
All mobile operators supports the USSD protocol?
Lorenzo
You need an USSD server/gateway in your mobile network operators environment, connected to the operators SS7 network. USSD messages can be sent either from mobile phone to USSD server or from USSD server to mobile phone. It is not possible to send an USSD message directly from one phone to another, you would need to relay the message via the USSD server.
USSD messages are not standardized, they are specific to the mobile network and the USSD-capable applications. However, there are some de-facto standard USSD messages understood by many HLRs for querying and configuring things like call forwarding.
USSD is transported via SS7 using the MAP protocol. The business logic implemented on top of MAP is bound to the actual protocol stack implementation. On the server side that could be hardware (interface cards) plus operating system drivers or software-only, e.g. a SIGTRAN-Stack, depending on the physical layer to be supported (E1, SDH over fiber, ATM or Ethernet). A sample application depends on the protocol stack it runs on. Look for sample applications from the vendor of your interface hardware or protocol stack. On the client side the USSD support is device-dependent, e.g. via J2ME JSR 120 "Wireless Messaging API".
USSD is not guaranteed to be delivered, especially not in roaming scenarios. That solely depends on your mobile network operator. If you do not have an agreement with the operator, he might firewall away your USSD messages, especially if he detects high volumes circumventing his pay-messaging services.