Last week I noticed some problems with DirectAccess by using UMTS/3G broadband network of a Dutch mobile provider (KPN). A number of IPv6 translation methods don’t work by default which results DirectAccess by broadband is not always guaranteed. Table below shows a comparison of the various telecom providers and supported IPv6 translation methods.
IPv6 Translation ISP Provider support matrix
| Provider | 6to4 | Teredo | IP-HTTPS |
| KPN (UMTS) | X(1) | X(2) | √ |
| Vodafone (UMTS) | √ | √ | √ |
| FRITZ (ADSL) | n/a | √ | √ |
- Teredo traffic—UDP destination port 3544 inbound and UDP source port 3544 outbound.
- 6to4 traffic—Protocol 41 inbound and outbound
In order to get DirectAccess working I contacted KPN on behalf of our customer. By default two Access Point Names (APN) were available; a third was introduced as part of the problem examination. As you can see KPN Default Internet is limited in supporting IPv6 translation methods required for DirectAccess. Even IP-HTTPS is only available after a manual action.
IPv6 Translation v.s. APN support matrix
| Access Point Name (APN) |
6to4 |
Teredo |
IP-HTTPS |
| KPN Default Internet |
X |
X |
√(1) |
| KPN Fast Internet |
X |
X |
√ |
| KPN Advanced Internet |
X |
√(2) |
√(2) |
- Manual configuration required
- Additional dial-up connection required
In order to get Teredo and IP-HTTPS at least working, the helpful KPN operator suggested the following ‘solution’ which introduces the third APN which supports both Teredo and IP-HTTPS.
- Setup a new dail-up connection
-
Select your modem to use. In my case HP Mobile Broadband Module modem
-
Enter *99# as dail-up phone number
-
Open Phone and Modem dialog box. Select your modem and open properties
-
Select Advanced tab and enter the following additional initialization string: +cgdcont=1,”IP”,”advancedinternet”
Now I am able to use KPN Advanced Internet APN which supports by default Teredo and IP-HTTPS and therefore able to initiate DirectAccess over KPN broadband Internet. Bear in mind your dail-up connection IPv6 properties is selected.
As DirectAccess using IP-HTTPS more or less as safety net plus the number of UMTS users is very limited; I recommend my customer using KPN Fast Internet as it supports IP-HTTPS by default and no additional dail-up connection is required. In the event that only Teredo is possible or supported; KPN Advanced Internet is the right choice for using DirectAccess.
