ITunes App Store for iOS not working on PlusNet (only)

[#1]

Really strange fault started this morning. I cannot download or update any iOS Apps either on my iOS devices or via iTunes. I spoke to AppleCare and they could not find any problem at their end, suggested I try another network on a different ISP. I have a VPN to an office network on another ISP and lo and behold everything works!
Have switched off router and modem (I am on FTTC) for half an hour but made no difference when I switched it back on again. Everything apart from iTunes Match and iOS app downloads appeears to work just fine.
Any ideas what is happening and is anyone else having this kind of problem?

[#2]

I just downloaded an app update on my iPhone and I updated it to 6.1.3 earlier and both worked fine.
Do you get any errors or does it sit there looking like it's trying to download?

[#3]

Dave, I was able to download and install the updates to 6.1.3 OK, it is just updates to Apps and iTunes match that will not work. Eventually I get Cannot connect to App Store message when trying to install app updates or new purchases.
The Mac iTunes iOS App Store IS now working (It wasn't before I left the router off for an extended period). However my iOS devices will not, unless I use the VPN to another Internet Provider.

[#4]

I am trying a Reset Network  Settings on my iPhone...
And it didn't make any difference.
The exact error is Cannot Connect to ITunes Store (on the iPhone).

[#5]

Working fine here...

[#6]

Very strange. Still not working on any of my iOS devices over PlusNet, but OK over VPN to another ISP. Must be something on PN network surely?
I am in Scotland, perhaps something to do with yesterday's known problems.

[#7]

Can you traceroute iTunes.apple.com ax.itunes.apple.com phobos.apple.com albert.apple.com gs.apple.com?
Also, try changing the DNS for your iPhone to 8.8.4.4 to see if that works.

[#8]

Here is a trace route from a working connection, for comparison:

Tracing route to e673.g.akamaiedge.net [23.62.114.217]
over a maximum of 30 hops:
  1    63 ms    99 ms    99 ms  192.168.1.254
  2    34 ms    32 ms    32 ms  lo0-central10.ptn-ag04.plus.net [195.166.128.193
]
  3    32 ms    32 ms    31 ms  link3-central10.ptn-gw01.plus.net [84.93.248.228
]
  4    68 ms    67 ms    31 ms  xe-10-1-0.ptw-cr01.plus.net [212.159.1.44]
  5    35 ms    30 ms    31 ms  10ge-linx.r1.lon1.uk.as5580.net [195.66.225.111]
  6    31 ms    32 ms    31 ms  eth1-3.core1.lon1.uk.atrato.net [78.152.44.102]
  7    38 ms    37 ms    36 ms  tge7-8.core1.ams2.nl.atrato.net [78.152.44.156]
  8    41 ms    49 ms    49 ms  eth2-5.edge1.ams5.nl.atrato.net [78.152.44.133]
  9    44 ms    36 ms    37 ms  eth1-6.edge2.ams5.nl.atrato.net [78.152.44.44]
 10    37 ms    37 ms    37 ms  78.152.38.234
 11    37 ms    37 ms    36 ms  a23-62-114-217.deploy.akamaitechnologies.com [23
.62.114.217]

[#9]

OK here! 
Just updated 5 apps on iTunes! 

[#10]

been fine here too on several iPads, never had any issue connecting to the App store or iTunes.

[#11]

It was working on some other iOS devices here for a while, was working on Mac, but isn't again now.
Trace route shoes it going to USA.

traceroute gs.apple.com
traceroute to gs.apple.com.akadns.net (17.171.36.30), 64 hops max, 52 byte packets
 1  192.168.0.1 (192.168.0.1)  1.649 ms  1.433 ms  2.455 ms
 2  lo0-central10.ptn-ag01.plus.net (195.166.128.190)  31.821 ms  30.357 ms  36.295 ms
 3  link11-central10.ptn-gw01.plus.net (84.93.248.148)  31.160 ms  31.451 ms  31.128 ms
 4  xe-1-2-0.ptw-cr01.plus.net (212.159.1.28)  29.446 ms  29.718 ms  29.212 ms
 5  te-4-2.car5.london1.level3.net (217.163.45.249)  29.621 ms  29.928 ms  29.886 ms
 6  ae-52-52.csw2.london1.level3.net (4.69.139.120)  112.113 ms  112.884 ms  112.363 ms
 7  * * *
 8  ae-44-44.ebr1.newyork1.level3.net (4.69.137.78)  114.995 ms  113.326 ms
    ae-41-41.ebr1.newyork1.level3.net (4.69.137.66)  114.144 ms
 9  ae-10-10.ebr2.washington12.level3.net (4.69.148.50)  113.486 ms
    4.69.201.62 (4.69.201.62)  113.935 ms
    ae-10-10.ebr2.washington12.level3.net (4.69.148.50)  112.869 ms
10  ae-1-100.ebr1.washington12.level3.net (4.69.143.213)  112.959 ms  112.921 ms  116.903 ms
11  ae-8-8.ebr1.washington1.level3.net (4.69.143.217)  112.660 ms  112.635 ms  112.651 ms
12  ae-1-13.bar2.charlotte1.level3.net (4.69.200.213)  112.843 ms  113.346 ms  112.612 ms
13  ae-3-3.car1.charlotte1.level3.net (4.69.200.222)  113.304 ms  117.945 ms  121.631 ms
14  apple-compu.car2.charlotte1.level3.net (4.71.126.86)  117.801 ms  115.239 ms  115.951 ms

[#12]

Works over the VPN, this is the trace route

traceroute gs.apple.com
traceroute to gs.apple.com.akadns.net (17.171.36.30), 64 hops max, 52 byte packets
 1  192.168.0.1 (192.168.0.1)  3.106 ms  1.842 ms  5.623 ms
 2  lo0-central10.ptn-ag01.plus.net (195.166.128.190)  34.559 ms  31.978 ms  34.670 ms
 3  link11-central10.ptn-gw01.plus.net (84.93.248.148)  33.510 ms  33.700 ms  31.126 ms
 4  xe-1-2-0.ptw-cr01.plus.net (212.159.1.28)  32.294 ms  29.861 ms  29.860 ms
 5  te-4-2.car5.london1.level3.net (217.163.45.249)  29.630 ms  30.772 ms  29.996 ms
 6  ae-52-52.csw2.london1.level3.net (4.69.139.120)  112.518 ms *  113.981 ms
 7  * * *
 8  ae-41-41.ebr1.newyork1.level3.net (4.69.137.66)  113.831 ms  115.462 ms
    ae-44-44.ebr1.newyork1.level3.net (4.69.137.78)  113.343 ms
 9  ae-10-10.ebr2.washington12.level3.net (4.69.148.50)  113.015 ms
    4.69.201.62 (4.69.201.62)  112.728 ms
    ae-10-10.ebr2.washington12.level3.net (4.69.148.50)  113.037 ms
10  ae-1-100.ebr1.washington12.level3.net (4.69.143.213)  112.825 ms  112.962 ms  113.065 ms
11  ae-8-8.ebr1.washington1.level3.net (4.69.143.217)  112.901 ms  113.716 ms  113.805 ms
12  ae-1-13.bar2.charlotte1.level3.net (4.69.200.213)  112.848 ms  113.014 ms  112.744 ms
13  ae-3-3.car1.charlotte1.level3.net (4.69.200.222)  116.932 ms  113.678 ms  112.902 ms
14  apple-compu.car2.charlotte1.level3.net (4.71.126.86)  116.768 ms  117.767 ms  116.076 ms

[#13]

As the traceroute from wykehamhouse shows, iTunes update traffic is handled by the Akamai CDN. So possibly the CDN node you're getting connected to is causing the problem. By using the VPN you may be ending up on a different CDN node which is working OK. In theory you should get the CDN edge node nearest to you, or more accurately to whichever Internet peering link your request pops out of.
gs.apple.com seems to go to the same place from Plusnet and VPN. But what about iTunes.apple.com and ax.itunes.apple.com (I think those both should go to Akamai edge nodes)?

[#14]

OK, after much faffing about, changing date and time on iOS devices and then trying to go to iTunes Store, which crashes it, then putting set time automatically ON again, I got the iOS devices to install apps again.
Still having similar problems with iTunes Match on iOS.
Plus the Washing Machine is not draining - is this related?  

[#15]

Hmmm! Apple stuck in the waste pipe?