Whats up with my Iphone 5,, 10.3.3

Now
I just signed with TPO about 3 weeks ago.. It's been a rough start, but that is to be
expected.

I was trying to send a text, but kept getting an error message, after talking to a
rep, I now get text is unavailable at this time, try later!!!!!

So again I called the "help" line and explained that their setup info for the Iphone
5 with IOS 10.3.3 does not look like mine..and it does not.

So here is what my 10.3.3 Iphone 5 shows... on setting, the cellular I have
CEllular Data, (on or off)

Under that I have Cellular Data Options,, there I have Enable LTE on\off
and Data Roaming, on\off, I have it off

that is all I have for cellular
This is what they told me to do.

How to access data Cellular > Cellular Data Options > Cellular Network.
Proxy:
Port:
Username:
Password:
Server:
MMSC: http://wholesale.mmsmvno.com/mms/wapenc
MMS proxy:
MMS port: 80
MCC: 310
MNC: 260
Authentication type:
APN type: default,mms,supl,wap
APN protocol: IPv4/IPv6
APN roaming protocol: IPv4/IPv6
Bearer: Unspecified

can anyone help me out!!!!
Best
Dave

Who is "TPO" (which carrier is that)?

I just checked my settings (iOS 11.0.1). My carrier is T-Mobile but I believe the settings should be similar. I have cellular on, LTE on, roaming off. I have no idea why you're even messing with those other settings? Texting works on my phone (7+). It certainly looks like whoever gave you those settings is over complicating things for you.

Let's start with the basics...

Like chscag asked - who is TPO?

In Settings -> Messages, do you have iMessage enabled? If so, does it have a blurb underneath that part or does it say "Waiting for activation"? If iMessage is enabled, do you also have "Send as SMS" enabled?

Who are you trying to send a message TO? Are they an iPhone user that uses iMessage?

If you open up Safari and try to open a web site, what happens?

Does the messaging work if you're connected to WiFi?

We need to figure out if you're trying to send a message as SMS or as data.

TPO is a low cost cell phone service provider and uses the ATT network.
IMessage is turned on as is SMS
I brought this Iphone 5 over from ATT, and had it unlocked... it could be that the unlock was not completed, even
though I am making calls on the TPO service.

Thanks Ember for your input...

When you answer the rest of my questions, I may have some additional thoughts for you...

Ember
As usual, after reading your message, It got me to thinking more, you gave me a good starting point.
I was trying to send a registration card via photo to the company.. it would not go through. I checked the
net and with "TPO" I finally sent a test txt to the company and they replied. So I then new that
messaging is working. Just awhile ago, I sent a Txt with a photo to a friend of mine, and it went through.
Why the photo of the registration card did not go through I have no idea.
About TPO, I think although it is a low very low priced cell provider, I think they are either owned by or
have some financial connection with ATT.
Also they do not have the most sophisticated help center. I have only used my cell phone when I'm on
the road, I'm either on my computer or on a land line most of the time, until just recently when I gave up
the land line... so now depending more on the cell phone.
It is interesting that even with the same model phone, and running the same IOS there can be
difference in what is present on the screen.
So as of now, I do have Txt\SMS, and it was you that got me off my butt to figure this out...
Best

Glad to hear that you have made at least some level of progress.

Are you able to open a web site with Safari while on the cell network?

There are two distinct aspects of messaging... SMS and MMS. SMS uses the voice portion of the cellular network and MMS uses the data portion of the cell network (this is why your cell phone is ALWAYS connected to the data portion of the network, even with WiFi enabled). With iMessage, things get a bit more complex because iMessage between iOS devices and Mac's uses the data network as an actual data program (with MMS, your carrier is able to distinguish between something like browsing the web and sending / receiving picture messages). Knowing that you were trying to send and MMS message (not an SMS as I had initially thought based on your description) immediately tells me to validate whether the actual data network is functioning properly.

Seems that you may have had some sort of a "quirk" with the messaging that was corrected once you successfully sent an SMS.

Incidentally - I just ported two AT&T post-paid phones over to Straight Talk. One went to the AT&T towers while the other went to Verizon towers. The AT&T tower-based phone took quite a while to fully port over. And, for the first hour at least (don't know how long it actually lasted because I went to sleep), that phone was only able to properly connect to the voice portion of the network. Even with that, SMS messaging didn't work at all (nor did MMS, iMessage, or any data-based app like Safari).

What's more, iMessage activation relies on communications in the background to validate the number of your phone. So, with no SMS/MMS connectivity on the device I was working with, iMessage wouldn't activate (even on WiFi). There are a lot of things that these devices do that are hidden from view. And that makes it harder to troubleshoot.

At least you're able to send and receive messages now. Glad to know it.

BTW...

TPO has nothing to do with AT&T. They use T-Mobile and Sprint towers.