Replace the legacy PBX and Twilio with one Rust-native communications stack.
For ISPs, telcos, MVNOs, and service providers who need unified voice, messaging, and OSS or BSS without paying a per-message tax to a foreign cloud, and without keeping a C softswitch specialist on staff.
Stack at a glance
- Lines of Rust (Voice)
- ~127K
- BitsPath .NET projects
- 20
- Router vendors (ISPChamp)
- 5
- Unsafe on the SIP path
- 0
What is the communications stack?
Three products, one operational surface.
The KaritKarma communications stack is three shipped products composed against the day-to-day reality of an ISP or telco operator in Bangladesh. BitsPath is the unified communications cloud (voice, mail, SMS, WhatsApp, CRM, analytics). BitsPath Voice is the pure-Rust carrier-grade softswitch that sits underneath it. ISPChamp is the software-defined BNG plus full OSS and BSS for subscriber operations.
BitsPath, BitsPath Voice, and ISPChamp inherit Wenme identity and Darwan authorization out of the box: one login, one permission model, one procurement cycle.
The problem
Communications infrastructure should not be this painful.
A legacy C softswitch is a maintenance tax
A large C codebase, constant security patches, and scarce specialists who charge a premium. BitsPath Voice answers the parsing surface with memory-safe Rust and a tenant-first schema. It carries less feature breadth, and the product page marks every capability live or planned so the trade is visible before a pilot.
Twilio bills grow without a ceiling
Per-message pricing with no upper bound. BitsPath BYOP lets you connect your own SMS, email, and WhatsApp providers. You pay provider rates directly, with zero delivery markup from us.
Hardware BRAS is a single point of failure
ISPChamp's software-defined BNG replaces six-figure Cisco and Juniper boxes with VPP and DPDK on commodity x86. Scales horizontally, fails partially, costs a fraction.
Fragmented tools, fragmented data
Voice in one tenant, SMS in a second, CRM in a third, ticketing in a fourth. BitsPath unifies every channel against a single contact record and shared analytics surface.
The products
Three shipped products, one platform underneath.
BitsPath
Unified Communications Cloud
Voice, webmail, SMS, WhatsApp, CRM, campaigns, inbox and analytics on one platform. Bring your own SMS, email and WhatsApp providers with zero delivery markup, on contracts under Bangladesh law.
BitsPath Voice
Pure-Rust Carrier-Grade Softswitch
About 127,000 lines of Rust across ten crates. SIP RFC 3261 over UDP, TCP, TLS 5061 and WebSocket, all listening at once. Every leg anchored on a B2BUA. SRTP on the SIP legs, DTLS-SRTP on the browser leg. Per-call recording encrypted at rest with a per-tenant retention sweep. No unsafe code on the SIP, B2BUA or RTP path.
ISPChamp
Software-Defined BNG and ISP Operations
Complete OSS and BSS with a software vBNG (VPP and DPDK) that replaces hardware BRAS. Multi-vendor routing (MikroTik, Cisco, Juniper, Huawei, ZTE), RADIUS, OLT management, CGNAT compliance, bKash and Nagad checkout.
Why KaritKarma
Built by people who run a network.
APNIC member AS 64005 with dedicated IPv4 and IPv6 blocks, announced over our own multi-homed BGP transit from a Tier-3 data centre in Dhaka, with a designated DR site. We do not just write the software, we run a network on it.
Pure-Rust PBX, no C runtime
BitsPath Voice is end-to-end Rust on the telephony path, with no unsafe code at all in the SIP parser, the transports, the B2BUA or the RTP and SRTP code. That is the whole surface a stranger's packet reaches, and it closes the buffer-overflow class of vulnerability by construction rather than by patching.
BYOP, zero delivery markup
Bring your own SMTP relay or Postal server for email, your own SMPP bind or aggregator for SMS, your own Meta WhatsApp Business account. You pay provider rates directly. We do not take a per-message cut.
Software-defined BNG on x86
Replace six-figure hardware BRAS with VPP and DPDK on commodity x86. Scale subscriber capacity by adding nodes, not by writing a Cisco purchase order.
KaritKarma vs the alternatives
What this stack replaces.
Side-by-side against the legacy or Western SaaS option that communications buyers in Bangladesh evaluate first.
Pure-Rust carrier softswitch (memory safe)
- KaritKarma
- BitsPath Voice
- Legacy or imported
- Open-source C softswitch
BYOP SMS, email, WhatsApp (zero markup)
- KaritKarma
- BitsPath
- Legacy or imported
- Twilio markup, per-message
Software-defined BNG on x86
- KaritKarma
- ISPChamp (VPP and DPDK)
- Legacy or imported
- Cisco ASR, Juniper MX
bKash and Nagad subscriber billing
- KaritKarma
- First-party in ISPChamp
- Legacy or imported
- Per-bank integration project
Single contact record across channels
- KaritKarma
- BitsPath unified CRM
- Legacy or imported
- HubSpot plus Zendesk plus Twilio
Attributed claims: BitsPath Voice figures and capability states taken from the bitspath-voice repository's own state-of-the-stack and engine reference documents, re-verified 2026-09-21. ISPChamp router-vendor coverage and the software vBNG data plane are verified in the ISPChamp codebase.
Buyer questions
Questions network teams ask first.
Six written answers so the technical briefing call starts on substance.
What is the KaritKarma communications stack?
How does BitsPath replace a legacy PBX and Twilio?
Can I migrate an existing SIP PBX to BitsPath Voice in place?
What is ISPChamp?
Is KaritKarma actually an APNIC member or just hosting on someone else's network?
Ready to unify the communications stack?
Get a personalized walkthrough of BitsPath with one of our specialists. No commitment required.