| Basic questions on how NowSMS would fit in |  Search
|
|
NowSMS Support Forums ⬆ NowSMS Support - MMS & Advanced Issues ⬆ Archive through June 06, 2005 ⬆ |
◄ ► |
| Author | Message | |||
| Anonymous |
Hi there, am a newbie trying to figure out some things about MMS. My aim is to write an MMS client for CDMA n/w, say working on a desktop and sending MMSs via HTTP through the gateway. The way I plan to do is to use this client to send MMS to the gateway and then use the pixplace to check if is proper. What I am stumped with is: 1. Where does Now SMS fit in ? If I were to be using Verizon Wireless, would I be able to configure Now SMS to use it ? 2. Have been looking at the format for the HTTP requests. From the reading I have done, I understand that one would have to send WSP encoded MMSs, right ? Typically, how would the HTTP POST requests look like ? Would there be a portion that is text format and the rest MMS stuff that is binary encoded. I am confused where the boundaries for each of these portions of the payloads are. I have been looking at the WSP specs. But, as the name implies.. it won't talk about HTTP. I am finding it difficult to understand how the WSP data fits in , in the HTTP payload. | |||
| Bryce Norwood - NowSMS Support Board Administrator Username: Bryce Post Number: 4034 Registered: 10-2002 |
It is more difficult to connect into CDMA networks for sending MMS than GSM networks. Well, perhaps not more difficult ... but we know a lot more about GSM and GPRS, because that is where our focus is. It is more difficult to use NowSMS as an MMSC in a CDMA environment. For the most part, you either need to be a mobile operator, or have a close partnership with a mobile operator, in order to facilitate this. However, there's no reason that you couldn't use NowSMS as an MMS gateway into Verizon. We support standard MMS protocols such as MM7 and MM4. But those require special accounts with the operator. The alternative is an MM1 connection, which in a GSM environment, we normally do over a GSM/GPRS modem. NowSMS includes quite a few optimisations for connecting to an operator MMSC over a GSM/GPRS modem. However, the same approach could be used in a CDMA environment ... it just takes some different configuration. Take a look at http://www.nowsms.com/howmmsworks.htm for a technical overview of how MMS works. Direct Delivery (NowSMS as an MMSC) is not really an option for you, because you need a binary SMSC connection, and those are hard to come by in the CDMA world. But, there is no reason that you couldn't use a CDMA modem instead of a GSM/GPRS modem to facilitate connecting to the operator MMSC. Let me explain ... You're probably not going to be able to add a CDMA modem to the NowSMS "SMSC" list. There are a few CDMA modems (like Multitech) that emulate a GSM modem interface. Because these modems do not support a binary SMS interface, you need an update to NowSMS v5.51 to work with them for sending text SMS only. (Please see http://support.nowsms.com/discus/messages/53/8153.html for specifics.) But it is not critical that the modem support SMS connectivity. You can leave the SMSC list blank in NowSMS and just ignore the warning messages about how the service will not work without any SMSC connections defined. The error really just means that you won't be able to send any SMS messages ... but if you can live with that, just ignore the warning message. The MMSC connection gets defined on the "MMSC Routing" page. See http://www.nowsms.com/documentation/ProductDocumentation/mms_notifications_and_c ontent/Connecting_to_operator_MMSC.htm#UsingGPRS for a reference to this type of configuration, and I'll explain here what would be different in a CDMA environment. In a GSM/GPRS environment, you can simply tell us which modem to use, configure the access point name (APN), and we will initiate a data connection with the modem automatically. This data connection allows us to make a TCP/IP connection into the operator network. In a CDMA environment, there is not an APN concept (that I am aware of anyway). So NowSMS can't program the modem directly to make the network connection. However, we can initiate a connection that you define using dial-up networking in Windows. You define a dial-up networking profile to make the TCP/IP connection to the operator network over the CDMA modem. And you select it in the "Network Connection:" field instead of selecting a modem directly. When NowSMS needs to deliver an MMS, it will automatically initiate that dial-up connection. The problem is, I don't know what number you configure your dial-up networking connection to dial in order to make this connection in a CDMA environment. And I don't know if there are any other extra modem initialisation commands that you need to configure in the dial-up profile. But if you can find that information out, then it would be workable. You would then also need to find out the MMSC Server URL, and the IP address of a WAP gateway through which to connect to the MMSC. (If the WAP gateway uses HTTP/WAP2 protocols, specify http://ip.address:port in the "WAP Gateway" field instead of just an IP address.) All this said, a lot of developers are just sending MMS messages to Verizon subscribers by sending them via SMTP. Because Verizon charges subscribers to receive an MMS message (outside of the US the billing model is usually that receiving an MMS is free, but you are charged for sending), they have a free SMTP gateway through which you can submit messages. You have to be careful about this however ... as spam is a concern ... they will go after you if you use this for blatant commercial purposes (especially if recipients complain). -bn | |||
| Anonymous |
Bryce, Thanks a lot for the detailed information. Truly appreciate it. Right now, I am still digesting all this info ;) However, certain things in your post grabbed my attention and here are my responses to those. [Bryce] In a CDMA environment, there is not an APN concept (that I am aware of anyway). So NowSMS can't program the modem directly to make the network connection. However, we can initiate a connection that you define using dial-up networking in Windows. You define a dial-up networking profile to make the TCP/IP connection to the operator network over the CDMA modem. And you select it in the "Network Connection:" field instead of selecting a modem directly. [/Bryce] yes. I can do that for my CDMA modem. Basically, if you are looking for a RAS dialup profile which can connect, that is possible. One question that intrigues me is, if the desktop is already connected via LAN or anything else, would you still need this Dial-Up connection ? Wouldn't sending MMSs be possible through any IP connection , no matter what the underlying interface to the internet is? [Bryce] When NowSMS needs to deliver an MMS, it will automatically initiate that dial-up connection. The problem is, I don't know what number you configure your dial-up networking connection to dial in order to make this connection in a CDMA environment. And I don't know if there are any other extra modem initialisation commands that you need to configure in the dial-up profile. [/Bryce] Yep. Possible, generally in the US, dial string of #777 is used. [Bryce] But if you can find that information out, then it would be workable. You would then also need to find out the MMSC Server URL, and the IP address of a WAP gateway through which to connect to the MMSC. (If the WAP gateway uses HTTP/WAP2 protocols, specify http://ip.address:port in the "WAP Gateway" field instead of just an IP address.) [/Bryce] Interesting. Am planning to use Verizon Wireless'. Will have to fish out that info. | |||
| Bryce Norwood - NowSMS Support Board Administrator Username: Bryce Post Number: 4046 Registered: 10-2002 |
There are two issues here. First, there is the fact that the operator wants to charge you for sending messages. They're expecting to see a connection from a phone. So by using the phone as a modem, we are connecting in to the operator network the same way that the MMS client on a mobile phone would. Second, operator MMSCs are generally firewalled off from the world so that they are only accessible when you are connected to the operator's network. So this approach is all about connecting in using the same protocols that a mobile phone would use. The MM7 protocol is defined for the purposes of connections from value added service providers (content providers) to send messages. And this connection is usually over the internet (sometimes with VPN security), but it can be a challenge to get an MM7 account with most operators, often because the operators do not have sufficient manpower for managing these types of accounts.
Interesting. The question will be whether #777 connects to a different network access point than what the MMS client (or browser for that matter) in the mobile phone connects to. In the GRPS environment, *99# is the number that is dialed. But there are also parameter options on it ... so it could be *99***2# to connect to a particular access point. The AT+CGCONT command is used to define access points before you connect. Most major mobile operators have several different access points. It is common for there to be one access point for WAP browsing from a client in the mobile phone, another for MMS traffic only, and a another for general internet access with people using the phone as a modem. So I'm wondering if there is a similar concept with the CDMA operators. I would expect that there would be. But the question is how to find this out. -bn | |||
| Anonymous Unregistered guest |
Got it. Makes sense.
There isn't. So, if a data session is up, the MMS client would go thru that instead of trying to set up one again, and if it tried to, it would fail on CDMA. But, that brings up a good question. If the mobile unit was already connected to the data n/w through a browser, then on GSM would it have to dial the MMS APN on top of an already existing data connection ? | |||
| Another Guy Unregistered guest |
You would then also need to find out the MMSC Server URL, and the IP address of a WAP gateway through which to connect to the MMSC. (If the WAP gateway uses HTTP/WAP2 protocols, specify http://ip.address:port in the "WAP Gateway" field instead of just an IP address.) </Bruce> Bruce, Newby here..... I have the Wap Gateway address. Why do I need the VZW MMSC URL? How would I find this out? | |||
| Bryce Norwood - NowSMS Support Board Administrator Username: Bryce Post Number: 4056 Registered: 10-2002 |
In GSM/GPRS, the phone registers with the GPRS network, but it doesn't get an IP address until it activates to a named access point. Over a single GPRS connection, a phone might have multiple IP contexts open, to different access points. (Early GPRS phones couldn't handle this, so if you were in the browser and received an MMS notification, it couldn't retrieve the MMS message until you exited the browser.) | |||
| Bryce Norwood - NowSMS Support Board Administrator Username: Bryce Post Number: 4057 Registered: 10-2002 |
On the subject of multiple APNs, I should probably explain one of the main reasons why they do this ... so that they can charge different data access charges on the different APNs. I should also explain that the modem interface of the phone only supports a single active APN connection. But software running on a phone itself could have other connections open. | |||
| Bryce Norwood - NowSMS Support Board Administrator Username: Bryce Post Number: 4058 Registered: 10-2002 |
Because in order to send the message, you need to transmit it to the MMSC for delivery. (Also, you need this URL when you are receiving MMS messages, because you need to acknowledge receipt to the MMSC in a separate transaction from the content retrieval.) In the GSM/GPRS world, you often find this information out by exploring the configuration settings in the phones. However, my experience has been that CDMA phones are far more locked down. I've done a little searching on the web, but I haven't turned up anything yet. Wait, I was about to give up for today, and I might have found a potential lead. I believe it might be http://mms.vtext.com/servlets/mms Or possibly the "servlets/mms" is not required. Unfortunately, when NowSMS tests its connection, the test only goes so far as validating the data connection to a WAP gateway. It doesn't validate that the MMS URL is good. All you can do is try sending a message. And if it doesn't work, enable the MMSWAPDEBUG.LOG (serial # page), so that we can take a closer look and see if that gives any clues. -bn | |||
