The 2014 INC5000 list is out - with 134 companies in telecom (including clients).
VoIP
Callis (now owned by C Spire) ($11M), Telesphere ($32M), Simple Signal ($11M), VoIP Innovations ($10M), Star2Star ($33M), iCore Networks ($46M, VoIP white label), Phone.com ($7.6M, #2857)
There are quite a few inter-connects, VARs, telecom agencies and several wireless consultancies.
PlanetOne (master agent @ $14M), BCM (agency, $13M), eSquared (agency, $6.6M), Network Solutions Services (agency with $13.5M), Sandler (master, $23M), Advantage Comm Gp (agency, $6M), AllConnex (VAR, $3.7M)
ISP, CLEC, fiber
FiberLight (fiber at $110M), Southern Light ($65M), Fibertech ($169M), PEG Bandwidth ($33M), Bluebird Network (ISP, $29M), Veracity Networks (FTTP, $34M), New Horizon Comm ($48M), Transbeam ($18M), TowerCloud ($27M), Zayo Group ($1B, #1300), Ideatek (ISP, $5M), Nexaccess.net (hosting, $11M), JAB Broadband (WISP roll-up, $109M), Granite (CLEC, $866M), NITEL (CLEC, $57M), Masergy ($170M), UNSI ($50M), HuntTelecom ($16M), Integra ($22M)
Miscellaneous; Overgroup (BSS, $3M), TELX (data center, $257M), Twilio ($52M), unifiedcommunications.com ($16M), CFN Services ($21M)
If you are on twitter, here is the INC5000 on twitter list