# AT+CHLD=2 responds +CME ERROR 30

**URL:** <https://forum.sierrawireless.com/t/at-chld-2-responds-cme-error-30/4511>\
**Category:** Legacy FX/FXT series\
**Created:** [June 17, 2010, 7:33am UTC](https://forum.sierrawireless.com/t/at-chld-2-responds-cme-error-30/4511 "2010-06-17T07:33:21Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![awneil](https://avatars.discourse-cdn.com/v4/letter/a/49beb7/32.png) [@awneil](https://forum.sierrawireless.com/u/awneil)\
**Post date:** [June 17, 2010, 7:33am UTC](https://forum.sierrawireless.com/t/at-chld-2-responds-cme-error-30/4511/1 "2010-06-17T07:33:21Z")

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Incoming voice call, auto-answered:

> [@](#):
>
> +CRING: VOICE
> 
> +CLIP: “07949578122”,129
> 
> +WIND: 9
> 
> OK  
> at+clcc
> 
> +CLCC: 1,1,0,0,0,“07949578122”,129
> 
> OK  
> at+chld=2
> 
> +CME ERROR: 30

> [@AT Commands Interface Guide for v7.4a](#):
>
> Meaning: No network service  
> Resulting from the following commands: +VTS, +COPS=?, +CLCK, +CCFC, +CCWA, +CUSD, +CCED

So it’s not documented as a response to AT+CHLD

Clearly, there is network service - because a call is up!

So what does this really mean?

I get the same on pre-pay SIMs from Vodafone, Orange, and O2 (haven’t tried T-Mobile yet) - all UK.

> [@ATI9](#):
>
> “DWL”,“V08b0g”,“”,“Wavecom”,54680,“071609 15:36”,“16bb6f5c”,“00010000”  
> “FW”,“B74s00gg.Q2686G”,“R74a00gg.FXT001”,“Wavecom”,2106632,“102809 12:57”,“7c687cd0”,“00020000”  
> “OAT”,“0.0.0”,“xxxxxxxxxxxxxxx”,“Antronics Ltd”,280808,“061610 17:47”,“26a49ff3”,“00260000”  
> -“M2M Studio”,“1.1.1.200911160856-R3160”  
> -“Open AT Embedded Software Suite package”,“2.31.0.RC1”  
> -“Open AT OS Package”,“6.31.0.03”  
> -“Open AT Firmware Package”,“7.4.0.a.200910291816”
> 
> OK

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<div class="post-metadata">

**Author:** ![awneil](https://avatars.discourse-cdn.com/v4/letter/a/49beb7/32.png) [@awneil](https://forum.sierrawireless.com/u/awneil)\
**Post date:** [June 18, 2010, 5:54pm UTC](https://forum.sierrawireless.com/t/at-chld-2-responds-cme-error-30/4511/2 "2010-06-18T17:54:44Z")

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> [@awneil](#):
>
> haven’t tried T-Mobile yet

I have now - the behaviour on T-Mobile is the same.

However, on Virgin (which is an MVNO using T-Mobile) the hold operation does work successfuly, and I can successfully dial a second call; but attempting to conference the 3 parties together (AT+CHLD=3) now fails

> [@](#):
>
> atd 07960 670095; – dial 1st call
> 
> +WIND: 5,1
> 
> +WIND: 9
> 
> +WIND: 2
> 
> OK  
> at+clcc
> 
> +CLCC: 1,0,0,0,0,“07960670095”,129 – 1st call is connected
> 
> OK  
> at+chld=2 – put 1st call on hold
> 
> OK – success!
> 
> atd 01256xxxxxx; – dial 2nd call
> 
> +WIND: 5,2
> 
> +WIND: 2
> 
> OK  
> at+clcc
> 
> +CLCC: 1,0,1,0,0,“07960670095”,129 – 1st call is on hold  
> +CLCC: 2,0,0,0,0,“01256xxxxxx”,129 – 2nd call is connected
> 
> OK  
> at+chld=3 – attempt to connect all calls (multiparty)
> 
> +CME ERROR: 30 – fails (undocumented reason)  
> at+clcc
> 
> +CLCC: 1,0,1,0,0,“07960670095”,129 – 1st call is still on hold  
> +CLCC: 2,0,0,0,0,“01256xxxxxx”,129 – 2nd call is still connected
> 
> OK

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<div class="post-metadata">

**Author:** ![awneil](https://avatars.discourse-cdn.com/v4/letter/a/49beb7/32.png) [@awneil](https://forum.sierrawireless.com/u/awneil)\
**Post date:** [June 24, 2010, 2:56pm UTC](https://forum.sierrawireless.com/t/at-chld-2-responds-cme-error-30/4511/3 "2010-06-24T14:56:36Z")

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The problem doesn’t seem to be in the Sierra Wireless stuff - I get similar results if I try it on my phone.

I guess it’s because I’m using pre-pay SIMs, and the networks don’t provision this on pre-pay?

I still think Sierra Wireless is giving the wrong error message, though…

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<div class="post-metadata">

**Author:** ![awneil](https://avatars.discourse-cdn.com/v4/letter/a/49beb7/32.png) [@awneil](https://forum.sierrawireless.com/u/awneil)\
**Post date:** [July 8, 2010, 10:33pm UTC](https://forum.sierrawireless.com/t/at-chld-2-responds-cme-error-30/4511/4 "2010-07-08T22:33:36Z")

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> [@awneil](#):
>
> Clearly, there is network service - because a call is up!
> 
> So what does this really mean?

It means that this particular network service (Multiparty) is not available - it’s not saying that there is no service at all!

This should at least be more cleary documented, and preferable a distinct error code.

> [@awneil](#):
>
> I guess it’s because I’m using pre-pay SIMs

Yes - on the networks that support it at all, it’s only available with a contract.

All of the UK networks’ Customer Service (sic) lines have been utterly hopeless on this - continually giving advice that was unhelpful at best, or just plain wrong! 😠

The summary seems to be:

Vodafone: Supported on Contract only, needs a call to Customer Service to enable it;  
Orange: Possibly supported on Contract only (unclear);  
T-Mobile: Not supported at all;  
O2: Not supported at all.