Have you tried security oriented distro Operator.iso by ussysadmin.org? It is based on knoppix and debian. Also it is one of the best network testing and pen testers tool?
AUDIO CODES MP-114 VOIP Gateway Open Box
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Grandstream GS-HT802 2 Port Analog Telephone Adapter VoIP Phone & Device, Black
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Cisco VG202XM Analog Voice Gateway VoIP -- [NEW/FULL KIT]
$76.00
Yealink T54W IP Phone, 16 VoIP Accounts. 4.3-Inch Color Display - Black
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Yealink W73H IP DECT VOIP Phone
$10.00
Polycom VVX 400 VOIP Phone VVX400
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New Cisco 7945G IP VoIP Gigabit GIGE Telephone Phone CP-7945G -
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Polycom VVX 401 Corded 12 Line PoE IP Phone VOIP (2200-48400-025)
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LOT OF 10 Cisco CP-7841-K9 VoIP 4-Line Business Phone w/ Stand Handset Cord
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Yealink SIP-T41P PoE Ultra Elegant VoIP Phone
$29.95