DSP, PVDM & Media Resources

The Cisco High-Density Packet Voice Digital Signal Processor (DSP) Module (PVDM2) enables Cisco Integrated Services Routers to provide high-density voice connectivity, conferencing, and transcoding capabilities in Cisco IP Communications solutions. PVDM stands for packet voice DSP module; it is the Cisco product name for the module that provides digital signal processing resources to a system. DSP stands for Digital Signal Processor; it is a generic Industry terminology. A PVDM module could be staffed with one or multiple DSPs. PVDM2-8 = 8ch (G), 4ch (H), 4ch (M) PVDM2-16 = 16ch (G), 6ch (H), 8ch (M) PVDM2-32 = 32ch (G), 12ch (H), … Continue reading DSP, PVDM & Media Resources

Scanario#21 – VG224 Fax Issues

Customer reported a fault that several fax machines which were working fine last week have suddenly stopped working. All they were getting for incoming faxes was just the header. No content of the actual fax. Rule of thumb – anything which was working before and not working now means something must have changed. I jumped on the main Voice gateway which was connected to the switch and the Fax machines were connected to the VG224. A typical depiction could be as follows: PSTN >> VGW >> SW >> VG224 >> FAX There were 3x E1 cards on the Voice gateway. … Continue reading Scanario#21 – VG224 Fax Issues

Scenario#1 – VG224 – Strange DTMF behaviour

Problem description: One of my customer reported an issue with their VG224. All Polycom conference phones connected to the Vg224 were facing an strange issue of DTMF tones not recognized by PSTN. Users trying to get into a MeetMe conference were havingĀ  tough time as their pin was not getting recognised. Analysis & Observations: This issue was passed onto me after some of my colleagues already spent few days trying all sort of things for resolution. I found out from the customer that the phones never worked properly ever since they hooked them in VG224. One thing was clear from … Continue reading Scenario#1 – VG224 – Strange DTMF behaviour