Acronyms and Definitions¶

ConnexCS uses standard telephony terminology in our Control Panel and documentation.

Find below the definitions for the most relevant telephony terms, along with some general networking terms and ConnexCS specific terms.

Term	Definition	Explanation
ACD \ ALOC	Average Call Duration \ Average Length of Call	The average length of calls. Average Call Duration or otherwise called Average Length of Call is a retrospective calculation of how long calls last, that is the mean average. Typically only connected calls are included in this calculation, so it is simply the total time that all of the calls were connected divided by the total number of connected calls.
ASR	Answer-Seisure Ratio	The call answer rates as a percentage (connected calls divided by total calls).
Channel	n/a	An ongoing live call on the system.
CLI	Calling Line Identification	Identifies the caller's telephone number, which is often displayed to the call recipient in the form of Caller-ID.
CPS (Flow Speed)	Calls Per Second	The number of allowed calls per second. ConnexCS uses this term and Calls Per Second (CPS) interchangeably.
CDR	Call Detail Records	In-depth information about calls that pass through a VoIP exchange. CDRs are a source data for billing and consumer tracking.
Codec	Coder-Decoder	Encodes and decodes data between analog and digital signals, with some form of compression.
DID	Direct Inward Dial	By assigning a public number to an internal location, outside callers can reach a destination without going through a PBX.
DTMF/MF4/Touch-Tone	Dual-Tone Multi-Frequency	A signalling system that connects points in the telephony network, typically between telephone equipment, communications devices, and switching centers. See Wikipedia DTMF for more details.
E.123	Specific Number Format	A standard that includes a number format beginning with a + followed by a country code and subscriber number.
E.164	Specific Number Format	As described by the ITU, the E.164 general format must contain only digits split as follows: Country code (1 to 3 digits) Subscriber number (max 12 digits).
FAS	False Answer Supervision	A kind of billing fraud, it bills a call for a length of time that was longer than the actual call duration.
FQDN	Fully Qualified Domain Name	A domain name, which also includes a hostname, that points to or references an IP. For example, sip.connexcs.com.
IVR	Interactive Voice Response	Sometimes known as a "phone tree," this allows callers to select different options that connect them to different end-points (For example, extensions or users) in your system.
Jitter	n/a	This refers to the variation in time between received packets. In a VoIP system, Jitter may explain voice quality issues such as robotic-sounding voices, static, or choppy audio.
LCR	Least-Cost Route	The practice of managing traffic in a VoIP network in the least expensive way. 'Expensive' can relate to the actual cost, or it can abstractly refer to time and effort.
LRN	Location Routing Number	Wikipedia LRN. A number portability system used to route NPA-NXX calls and allow the receiving carrier to find the price of the call, not the destination number.
MOS	Mean Opinion Score	This score can show the general call quality of a system, a carrier, or a customer.
NAT	Network Address Translation	This is a networking practice that allows private IPs in a defined network to share a public IP that can route over the internet, helping to conserve the dwindling supply of public IPs.
NER	Network Effectiveness Ratio	Measures a network's ability to deliver phone calls independent of user actions like a terminal reject.
NPA-NXX	Numbering Plan Area-1st 3 digits	The number is followed by four more identifying digits, making it NPA-NXX-XXXX. The 'N' in NXX is different because it represents digits from 2 9 instead of 0–9, as it's with 'X'. See USA Routing for further explanation.
PDD	Post-Dial Delay	The time between the last digit dialled and a ringer or equal action on the other end. This is useful to check to see if a carrier is slow to connect a call.
PSTN	Public Switched Telephone Network	A broad term that encompasses most telephone networks, including telephone lines, mobile networks, and communication satellites.
RTP	Real-time Transfer Protocol	A network protocol used to move media across IP-based systems.
SIP	Session Initiation Protocol	A TCP/IP-based network protocol used in VoIP telephony to establish connections for telephone calls.
SIP Trace	n/a	A log of SIP signalling messages, this is an essential tool for troubleshooting registration, call completion, and other issues.
Transcoding	n/a	Converts file from one format to another. In ConnexCS, this refers to the process of converting audio from one codec to another, often when there is low-bandwidth.
Channel	n/a	Channels are analogous to dialogs. Channels are counted even if the call wasn't connected or even ringing hasn't begun. It's counted even if the call geeing setup. For example, if 100 channels exist, it means 100 active calls exist.
Dialog	n/a	A Dialog is a single call.
2FA/TFA	Two-Factor Authentication	A login method requiring two types of verification, usually a password plus a code or approval from a device. This adds an extra security layer beyond just a password.
Web Auth N / FIDO2	Web Authentication / Fast Identity Online 2	A modern authentication standard that allows secure, passwordless logins using methods like security keys, biometrics, or device-based credentials. It reduces reliance on passwords and strengthens protection against phishing
ASR+	Answer Seizure Ratio+	ASR Plus is a proprietary ConnexCS technology that filters known failed, non-existent / working numbers between the customer and the terminating, or destination, carrier.
AnyEdge	n/a	It balances the traffic between the SIP servers and the customers.
Spam Scout Scoring	n/a	It blocks Spam calls based on the CLIs.
IPQS	IP Quality Score	Tt blocks the calls based on the spam score. The spam score is provided by a third party IPQS.
PAID	P-Asserted-ID	A header field in the SIP INVITE that has the identity of the caller (typically used for caller-ID / network identifier). It shouldn't be delivered to the end-user.
RTP Firewall	n/a	It will bypass the media Firewall.
STIR/Shaken	STIR: Secure Telephone Identity Revisited SHAKEN: Signature-based Handling of Asserted Information Using toKENs	Required step for call origination providers to authenticate and validate caller identities.
CIDR	Classless Inter-Domain Routing	A method of allocating IP addresses and routing that replaces the older class-based system. It uses a suffix (e.g., /24) to show how many bits define the network portion of the address. For example, 192.168.1.0/24 represents 256 IP addresses from 192.168.1.0 to 192.168.1.255.
STUN	Session Traversal Utilities for NAT	Clients can use STUN to determine their external IP address and update SIP packets accordingly.
ALG	Application Layer Gateway	NAT devices can rewrite SIP packets to use external IP addresses, though this method is unreliable.
Far-end NAT Traversal	n/a	The system can detect and adjust for NAT by checking IP headers and assuming the correct external IP address.
UAC	User Agent Client	Acts as a client, typically used when sending calls out.
UAS	User Agent Server	Acts as a server, typically used when receiving calls.
Tech Prefix	n/a	A unique code assigned to each customer sharing an IP, enabling the switch to identify the route, correctly route calls, and distinguish between different rate cards.
Dial String	n/a	Restricts outgoing calls to numbers matching the defined dial string or pattern. If left blank, all calls are allowed
Dial String Prefix Set	n/a	A collection of commonly used prefixes (e.g., for the UK) that can be selected for customers, avoiding the need to enter each prefix individually.
FTC DNC Report ANI Block (USA)	n/a	Blocks known spam numbers.
DNO	Do Not Originate	Blocks numbers that should never be used for outgoing calls, including spoofed, unassigned, unallocated, or inbound-only numbers. Helps prevent illegal, fraudulent, or malicious traffic.
DNC	Do Not Call	The customer won't be able to able to dial the numbers in the specified DNC list.
TCPA Litigator DNC	TCPA: Telephone Consumer Protection Act. DNC: Do Not Call*	Prevents calls to phone numbers reported as TCPA litigators, reducing the risk of legal action under the Telephone Consumer Protection Act (TCPA).
SST	SIP Session Timer	Prevents ghost or long-duration calls.
Active RTCP Generation	n/a	Controls RTCP packet generation
RTP Codec	n/a	Manages audio/video codecs
Ptime(ms)	Packetization Time	Sets how much audio/video data each RTP packet carries; higher values = longer chunks, lower = shorter.
ASR+ (Low)	Answer Seizure Ratio+ Low	Active on 30% of calls
ASR?	n/a	When ASR+ gets enabled on the provider card
ASR+?	n/a	When ASR+ gets enabled on the provider card, only known connected calls pass-through specific providers
ASR++	n/a	Only known connected calls pass-through
Channel Breach	n/a	This will identify instances when customers have exceeded your preset thresholds.
404 Hits	n/a	It indicates the number of times an unavailable URL on your website has been accessed.
200 Hits	n/a	It indicates the number of successful requests.
No Matches	n/a	It indicates the number of misses.
FTC Block	n/a	It indicates the number of calls blocked by the FTC Block.
CPS Breach	n/a	When a customer is passing more calls per second than permitted.
KYC	Know Your Customer	A process used to verify the identity of customers to prevent fraud, money laundering, or other illegal activities.
Circuit Test	n/a	For trouleshooting purposes.
First Reply Timeout	n/a	Carrier initial response time
PDD Timeout	Post-dial delay limit	Time for the carrier to respond to the call before trying another.
Ring Timeout	n/a	Time the call rings after carrier selection.
Code Consistency	n/a	Identifies route quality and detect carriers who may misrepresent call outcomes.
Failover	n/a	Lists calls that failed with this carrier but succeeded with another, helping troubleshoot carrier issues and identify FAS.
Reverse LCR	n/a	First, it selects the most expensive route.
Tier	n/a	Distributes calls across rate cards based on assigned weights.
LCR Performance	n/a	Chooses lowest-cost carriers, prioritizing those with better performance.
Max Duration	n/a	Ends calls after a set time or via SIP Ping checks if the other side is still active.
RTP Timeout	n/a	Ends calls if no RTP (audio) is detected for a set interval; not effective in direct RTP mode.
CPS Spike Buffer	n/a	Spreads sudden spikes of calls over time by buffering, then releasing them at the set calls-per-second rate.
Balance Disconnect	n/a	Checks balance every 60s and disconnects calls if balance plus debit limit drops below $0.
TTS	Text-to-Speech	Converts your text intto audio.
OCN	Operating Company Number	A unique identifier assigned to telecommunications service providers.
FRN	Firm Registration Number	A registration number used to identify a company or firm in official records.
SMTP	Simple Mail Transfer Protocol	Standard protocol used to send, relay, and route emails between mail servers and clients.
Cluster	n/a	Group servers to share information such as dialogues and throughput.
UAC Auth	n/a	Enables ConnexCS to register as a UAC (rather than a UAS) with upstream providers with a username and password.
WebRTC	Web Real Time Communication	Enables real-time voice, video, and data sharing directly in web browsers without plugins.
TLS	Transport Layer Security	Secures communication over networks by encrypting data and ensuring privacy and integrity.
TCP	Transmission Control Protocol	Ensures reliable data delivery with error checking, acknowledgments, and retransmissions.
UDP	User Datagram Protocol	Faster but unreliable; sends data without guaranteeing delivery or order, commonly used for streaming and VoIP.
DNS	Domain Name System	Converts domain names into IP addresses so computers can find each other on a network.
TTL	Time To Live	Specifies how long data (like DNS records or IP packets) remains valid before being discarded or refreshed.
A Record	Address record	Maps a domain name to an IPv4 address.
SRV Record	Service record	Specifies the host and port for specific services (e.g., SIP, XMPP) within a domain.
SPOF	Single Point Of Failure	A component whose failure would stop the entire system from working, making it a risk for reliability.
MRC	Monthly Recurring Charges	A fixed monthly fee charged for a service.
SIP Profile	n/a	Groups users who share the same features and services when logging in via SIP.
Barge Group	n/a	Allows a user to listen in on conversations of a specified group using the Barge feature.
Reseller Account	n/a	Allows carriers to sell their services through resellers or agents.
CPM	Calls Per Minute	The amount of calls sent in any single minute.
Parallel (Hunt Groups)	n/a	Rings a call to all members of the group simultaneously.
Sequential	n/a	Routes a call in a sequential order based on the order under Group Members.
AKey	Application Key	It's a secret key that's used to authenticate your application with Duo Security.
PWA	Progressive Web Application	A type of web app that can be installed on a device as a standalone application.
Dial Code/Destination	n/a	Allows quick lookup of country codes, number types (mobile/landline), and sometimes the provider.
PKI	Public Key Infrastructure	For authentication of calls.
ATIS	Alliance for Telecommunications Industry Solutions	A standards organization that develops technical and operational standards for the ICT industry, including telecom, 5G, and network interoperability.
CAs	Certificate Authorities	Provide SHAKEN certificates
STI-PA	Secure Telephone Identity – Policy Administrator	Manages and enforces STIR/SHAKEN policies to verify caller identity and reduce fraudulent or spoofed calls.
SPC	Service Provider Code	A unique code used to identify a service provider within telecom networks.
NCEA	National Exchange Carrier Association	Provides services, numbering resources, and regulatory support to telecom carriers in the U.S.
Restful JSON	n/a	Uses REST principles to exchange data in JSON (JavaScript Object Notation) format between clients and servers.
CRUD	Create, Read, Update, Delete	The four basic operations of persistent storage in databases and applications.
SSL	Secure Sockets Layer Certificates	Digital certificates that encrypt data between a web server and browser and verify the server’s identity.
HSTS	HTTP Strict Transport Security	Instructs browsers to only connect to a website using HTTPS, preventing insecure HTTP connections.
OCSP Stapling	Online Certificate Status Protocol	Server provides certificate status to browsers, reducing separate OCSP requests.
PHC	Password Hashing Competition	Competition to identify strong, secure password hashing algorithms.
TOTP	Time-Based One-Time Password, RFC 6238	Generates short-lived, time-based passwords for two-factor authentication.
ICMP Ping	Internet Control Message Protocol	Sends packets to check if a host is reachable and measure response time.
MTR	My Traceroute	Tools to trace the route and measure latency between source and destination.
IDS / IPS	Intrusion Detection/Prevention System	Monitors network traffic to detect (IDS) or block (IPS) malicious activity.
SSML	Speech Synthesis Markup Language	Allows controlling pronunciation, pauses, formatting of acronyms, dates, times, and censoring in TTS audio output.
Internal Number Block	n/a	Ensures number allocations are managed efficiently.
Alias	n/a	Rewrites the destination number partially or completely before further processing.
MAC	Media Access Control	A unique hardware address assigned to a network interface for communications on a local network.
IMEI	International Mobile Equipment Identity	A unique number assigned to mobile devices to identify them on cellular networks.
UUID	Universally Unique Identifier	A 128-bit identifier used to uniquely identify objects or information in computer systems.
Network Latency	n/a	Measures data travel delay.
Application Latency	n/a	Primarily server-side processing delay, independent of network transmission times.
SIP Ping Latency	n/a	Combines network latency and SIP server processing delays.
VoIP Latency	n/a	The time it takes for a voice packet to travel from sender to receiver in a VoIP call.
Ofcom	Office of Communications, UK	Independent authority regulating and enforcing UK communication laws, setting rules, and protecting public interest.
TRAI	Telecom Regulatory Authority of India	Independent authority regulating India’s telecom sector, enforcing laws, capping tariffs, and promoting pricing transparency.
ACMA	Australian Communications and Media Authority	Independent authority regulating communications and media services, managing airwaves, licensing, and enforcing rules in Australia.
MIIT	Ministry of Industry and Information Technology, China	Governs China’s telecommunications sector, sets and enforces regulations, and handles licensing for electronic, digital, and satellite communications.
GDPR	General Data Protection Regulation	Legal framework governing the collection, processing, and storage of personal data of EU residents, with strict enforcement and heavy penalties for violations.
RTCP	RTP Control Protocol	Does not carry media itself but reports delivery and quality statistics for
Smokeping / Long-Running Pings	n/a	Sets continuous pings to track long-term trends in customer or carrier latency.
Call Recording / Packet Capture	n/a	Records calls and captures packets on customer or carrier ends for analysis and comparison.
MI Termination	n/a	Ends calls when no audio is detected or when the dialog is closed, sending BYE messages to both parties.
Ping Timeout	n/a	Ends calls if the originator or receiver fails to acknowledge periodic SIP OPTION packets, preventing long-duration inactive calls.
SRTP	Secure Real-Time transport	Encrypts and authenticates real-time audio and video streams, ensuring secure voice and video communications over IP.
SMPP	Short Message Peer-to-Peer	Protocol for exchanging SMS messages between Short Message Service Centers (SMSC) and external entities like applications.
SMS	Short Message Service	Standard service for sending text messages between mobile devices.
Guard Rails	n/a	In AI, guardrails are rules or constraints that guide the model’s behavior to ensure safe, reliable, and context-appropriate outputs.
LATA	Local Access and Transport Area	Calls rated based on Local Access and Transport Area boundaries.
RC	Rate Center	The specific geographic rate center in the U.S. tied to the prefix.

ACD Calculation Method¶

graph TD
A[ACD Calculation] -->B[Correct Method]
A[ACD Calculation] -->C[Incorrect Method]
B -->D[Total Duration- answered calls /  Total Connected-answered calls]
C -->E[Total Duration / Total Calls]

ASR Inference¶

S.No	ASR Score	Inference
1.	60% and above	Exceptionally good
2.	40% to 50%	Acceptable
3.	Less than 40%	Poor

ASR Calculations¶

ASR Calculation = Total Connected / Total Calls
Strict ASR (Removing NER) Calculation = Total Connected / Non-carrier failure
NER Calculation = Client Side Response Codes / Client + Server Codes
Channels = CPS * ACD

CLI vs PAID¶

PAID is the address of the person who placed the call. This is same as the address in the "From" header, but it may change if the caller uses several identities and needs to represent the one that applies to the destination.

Example

Consider a call from [email protected] to the PSTN, where the P-Asserted-Identity field can be changed to the "alice" phone number.

CLI gives the calling phone's number to the party receiving the call. CLI is used to determine the caller or the place where a call originated.

The P-Asserted-Identity contains the caller id information for the call on the INVITE SIP packet. P-asserted-ID header may contain either Tel URI or SIP URI. For CLI identification purposes multiple P-Asserted-ID headers should not be used unless there is a P-asserted-ID containing Tel URI and/or a P-asserted-ID containing SIP URI and user=phone. In this case both type of URIs must contain the same phone number. If none of the above exist and contain a valid E.164 number, CLI will not be considered valid.

Missed Call Traffic¶

Missed Call Traffic is placing calls which DONT connect and / or have a VERY SHORT duration.

It's not advisable not to have large volumes of Missed Call Traffic.