Polycom 1725-16843-001 manual Use of IP Networks through the Pstn, Echo cancellation

Models: 1725-16843-001

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Safety Notices

Safety and Compliance (continued)

New Zealand Telepermit

PTC General Warning

The grant of a Telepermit for any item of terminal equipment indicates only that Telecom has accepted that the item complies with minimum conditions for connection to its network. It indicates no endorsement of the product by Telecom, nor does it provide any sort of warranty. Above all, it provides no assurance that any item will work correctly in all respects with another item of Telepermitted equipment of a different make or model, nor does it imply that any product is compatible with all of Telecom’s network services.

The Use of IP Networks through the PSTN

Internet Protocol (IP) by its nature introduces delay into speech signals as each data packet is formulated and addressed. Telecom Access Standards recommends that suppliers, designers and installers using this technology for calls to or from the PSTN refer to ITU E Model requirements in the design of their networks. The overall aim is to minimise delay, distortion and other transmission impairments, particularly for those calls involving cellular and international networks, which already suffer extensive delay.

Echo cancellation

Echo cancellers are not normally required in the Telecom PSTN because geographic delays are acceptable where CPE return loss is maintained within Telepermit limits. However, those private networks making use of

Voice over IP technology are required to provide echo cancellation for all voice calls. The combined effect of audio / VoIP conversion delay and IP routing delay can cause the echo cancellation time of 64 mS to be required.

Connection of this Polycom VVX 1500 VoIP Video Telephone to the Telecom network

All samples of this Polycom VVX 1500 VoIP Video Telephone connected to the Telecom network must be modified as described in KTL Test Report number 8A1710ANZ1 failure to do so will lead to the cancellation of this Telepermit.

UAE

TRA Registered No: 0017802/09

Dealer No: 0017133/09

Polycom, Inc.

Safety Notices - 157

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Polycom 1725-16843-001 manual Use of IP Networks through the Pstn, Echo cancellation