Avaya 1692 IP - Manual (Page 29)

1692 IP Conference Phone User’s Guide Nov 2009 29
Safety and Compliance (continued)
New Zealand Telepermit (continued)
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.