Доброго дня, уважаемые.
Не напомнит ли кто, в каком документе от Unify упоминается, что при подключении продуктов от Unify к SIP service provider необходимо использовать OpenScape Session Border Controller? Вот чудится мне, что я где-то видел такую чёткую рекомендацию, но найти не могу.
?

День добрый, скорее всего в документации о войсе.

В общем, нашел достаточно близкое упоминание в "OpenScape SBC V9, Administrator Documentation", page 23:

Untrusted WAN networks for which an SBC is required are:
• Internet
• SIP Service Provider Network
• Extensions of corporate IP networks to remote locations or remote users
which the customer’s IT organization does not consider sufficiently
secure, thus further security measures are necessary for VoIP
deployment.
Trusted WAN networks for which an SBC is optional are:
• Virtual Private Networks (VPNs). If OpenScape SBC is used in a trusted
WAN network that uses VPNs, since OpenScape SBC can support only
a signal VPN connection, a VPN concentrator must be used on the
access side of the OpenScape SBC.
• Extensions of corporate IP networks to remote locations or remote users
which the customer’s IT organization does consider sufficiently secure,
thus either no further security measures are necessary or there are limited
select security considerations.

Меня устроило.