C4 Communications partners with the following Telecommunication Service Providers to offer our clients the right solution.

MegaPath
Netwolves
One Communications
Optimum Lightpath
Paetec
PGi
Qwest
Savvis
Sprint Nextel
TelePacific
Time Warner Cable
tw telcom
TNCI
Verizon Business
Verizon Telecom
Windstream
XO Communications

AboveNet
ACC Business
Broad Sky Networks
Broadview Networks
CenturyLink
Comcast
Copper Conferencing
Covad
Cypress Communications
EarthLink Business
Global Crossing
gtt Global Telecom
Intercall
Internap
Level 3
MASERGY
McGraw Communications