Some devices enable full duplex, which is the ability of the speaker to be heard by another party when they are also speaking at the same time. You might have experienced this when you cut off or clipped the other party on some speakerphones. Although full duplex is becoming more common, companies are still using less expensive equipment to keep costs under control on a per-user basis. If your audience is another company, your quality might be degraded due to their equipment standards or vice-versa. The third issue is your corporate firewall.
Firewalls present significant challenges to speed and packet sequences.
All firewalls are not equal. Some might enable Internet audio, and others might block the packets. People using the Conference Center need to understand their own corporate firewall as well as the other company's firewall. When speed and packet sequences are slowed or altered, this directly impacts the quality of the audio transmission. PlaceWare is most concerned with quality of the audio.