User's Manual

ManualsBrandsAvaya ManualsIP DeskphonesAvaya Communication Server 1000 IP Phones Fundamentals

391

392

393

394

395

396

397

398

399

400

Telephony features 395

It is possible to enable both PSK SRTP on the IP Phone and configure

USK SRTP at the Call Server. If USK SRTP does not negotiate for a call,

PSK SRTP attempts to negotiate during a call. If the two endpoints for the

call have PSK SRTP enabled, the call is encrypted using PSK SRTP.

By default, Media Security is enabled on the system. To configure USK

SRTP, see “USK SRTP configuration” (page 395) . To configure PSK

SRTP on the IP Phone, see “PSK SRTP configuration” (page 395) .

USK SRTP configuration Use LD 17 to configure a system-wide Class

of Service parameter for IP Phones called Media Security System Default

(MSSD). The system default value is one of the following:

•

Always Secure IP (MSAW)

• Best Effort (MSBT)

• Never (MSNV)

When you change the MSSD parameter, the system updates any IP

Phones that have a Class of Service value of MSSD to use the new MSSD

parameter.

Use LD 11 to configure the Media Security Class of Service on each IP

Phone. The IP Phone can have any of the following values:

•

MSSD

•

Best Effort

•

Always

•

Never

For more information about configuring system-wide Media Security and

configuring Class of Service, see Security Management Fundamentals

(NN43001-604).

PSK SRTP configuration The SRTP PSK (Pre-Shared Key) media

encryption feature provides encrypted media. A preshared secret is

embedded in the Nortel IP Phone to generate and to exchange encryption

parameters without any Call Server involvement. This feature provides

SRTP capabilities to IP Phones managed by call servers, which do not

support SRTP USK (UNIStim Key). The SRTP PSK feature must not be

used in networks where phone-to-phone one-way delay is greater than

200 ms.

You can configure an SRTP PSK payload type ID for exchanging SRTP

PSK encryption parameters, either manually or by using automatic

provisioning. You cannot manually configure the SRTP PSK payload type

Nortel Communication Server 1000

IP Phones Fundamentals

NN43001-368 05.06 30 April 2010