Applies ToOffice 365 operated by 21Vianet - Small Business Admin Office 365 operated by 21Vianet - Admin Skype for Business Online operated by 21Vianet Skype for Business Online operated by 21Vianet - admin centre

Note:  This article applies only to Office 365 operated by 21Vianet in China. All other customers should see Set up Skype for Business Online .

To set up your network for Skype for Business Online:

  1. Add CNAME (alias) and SRV (service) settings to your Domain Name System (DNS) server.

  2. If you have an external firewall or proxy server, configure it to allow Skype for Business traffic.

  3. Test your DNS and firewall settings.

Step One: Add DNS settings

If you’re using your own domain name, add these entries to your external DNS server:

Type

Host name

Destination

TTL

CNAME

sip

sipdir.online.partner.lync.cn

1 hour

CNAME

lyncdiscover

webdir.online.partner.lync.cn

1 hour

Type

Service

Protocol

Port

Weight

Priority

TTL

Name

Target

SRV

_sip

_tls

443

1

100

1 hour

yourDomainName

sipdir.online.partner.lync.cn

SRV

_sipfederationtls

_tcp

5061

1

100

1 hour

yourDomainName

sipfed.online.partner.lync.cn

See DNS setting details for the features affected by each record.

If you have a firewall that blocks external SRV queries, add these entries to your internal DNS server as well:

Type

Host name

Destination

TTL

CNAME

sip

sipdir.online.partner.lync.cn

1 hour

CNAME

lyncdiscoverinternal

webdir.online.partner.lync.cn

1 hour

Type

Service

Protocol

Port

Weight

Priority

TTL

Name

Target

SRV

_sip

_tls

443

1

100

1 hour

yourDomainName

sipdir.online.partner.lync.cn

Step Two: Configure your firewall or proxy server

If you have an external firewall or proxy server, define rules for Skype for Businessports, outgoing connections, and IP address ranges.

Ports

Open the following ports in your organization’s external firewall:

 Port

Protocol

Direction

Usage

443

STUN/TCP

Outbound

Audio, video, and application sharing sessions

443

PSOM/TLS

Outbound

Data sharing sessions

3478

STUN/UDP

Outbound

Audio and video sessions

5223

TCP

Outbound

Skype for Business mobile push notifications

50000-59999

RTP/UDP

Outbound

Audio and video sessions

Outgoing connections

Create a rule that allows outgoing connections (TLS and HTTPS) for all users to these locations:

  • pipe.skype.com

  • skypemaprdsitus.trafficmanager.net

  • *.partner.microsoftonline.cn

  • *.partner.microsoftonline-p.cn

  • *.onmschina.cn

  • *.sharepoint.cn

  • *partner.outlook.cn

  • *partner.lync.cn

Set the HTTP/SSL time-out value to eight hours.

IP address ranges

See URLs and IP address ranges for Office 365 operated by 21Vianet.

Step Three: Test your settings

Test your DNS settings:

  1. Go to the Microsoft Remote Connectivity Analyzer.

  2. On the Office 365 tab, choose Office 365 Skype for Business Domain Name Server (DNS) Connectivity Test, and then click Next.

  3. Enter the sign-in address that you use when you sign in to Skype for Business Online (for example, bob@contoso.com), and then start the test.

DNS setting details

This table shows the Skype for Business features affected by each DNS setting.

Type

Host name or service

Features affected

CNAME

sip

Skype for Business desktop client autodiscover and sign-in

CNAME

lyncdiscover

lyncdiscoverinternal

Skype for Business mobile client autodiscover and sign-in

SRV

_sip

Skype for Business IM and presence integration with Outlook Web App

Authenticated user sign-in with Lync Web App

SRV

_sipfederationtls

Supports adding Skype for Business users in other organizations to the Skype for Business Contacts list.

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