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Safety Notices
Safety Notices - 5
New Zealand Telepermit
Polycom SoundPoint IP670 VoIP Telephone PTC 220/08/063
PTC General Warning
1. 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
2. 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.
The Use of Voice Compression through the PSTN
3. Because of the extensive delay already experienced when calling cellular and international networks, some of
which is already caused by their use of voice compression technologies. Telecom Access Standards will only
approve G711 voice technology for use on the PSTN. G711 is an ‘Instantaneous Speech encoding Technique’
whereas G729 and all its variants are considered ‘Near Instantaneous’ introducing additional delay into the
speech signal.
Echo Cancellation
4. 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.
Modification of this Polycom SoundPoint IP670 VoIP Telephone for the New Zealand Network
5. All samples of Polycom SoundPoint IP670 VoIP Telephones connected to the Telecom network shall be
equipped with the following software batch Rev 3.0.2.0917. Equipped with this software batch the IP telephone
is known to comply with the New Zealand speech transmission plan.
Korean Compliance
Safety and Compliance (continued)