# Asterisk, Twilio Elastic SIP Trunking vs CallTower Comparison

| | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Star Rating** | 4.6 out of 5 | 4.3 out of 5 | 4.3 out of 5 | 
| **Total Reviews** | 59 | 10 | 373 | 
| **Largest Market Segment** | Mid-Market (50.0% of reviews) | Small-Business (50.0% of reviews) | Mid-Market (63.6% of reviews) | 
| **Entry Level Price** | $0.02 per minute | No pricing available | No pricing available | 

---
## Top Pros & Cons

### Asterisk

Pros:
- Customer Service (1 reviews)
- Easy Integration (1 reviews)

Cons:
- Complex Processes (2 reviews)
- Customer Service (1 reviews)

### Twilio Elastic SIP Trunking

**Not enough data**

### CallTower

Pros:
- Customer Support (65 reviews)
- Helpful (57 reviews)

Cons:
- Customer Service (19 reviews)
- Poor Customer Support (16 reviews)

---
## Ratings Comparison
| Rating | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
  | **Meets Requirements** | 9.0 (45 reviews) | 9.3 (9 reviews) | 9.0 (290 reviews) | 
  | **Ease of Use** | 7.8 (47 reviews) | 8.1 (9 reviews) | 8.8 (295 reviews) | 
  | **Ease of Setup** | 7.5 (37 reviews) | 6.7 (6 reviews) | 8.5 (264 reviews) | 
  | **Ease of Admin** | 7.9 (34 reviews) | 8.3 (6 reviews) | 8.4 (243 reviews) | 
  | **Quality of Support** | 8.3 (38 reviews) | 8.1 (7 reviews) | 8.7 (286 reviews) | 
  | **Has the product been a good partner in doing business?** | 8.3 (27 reviews) | 8.1 (6 reviews) | 8.9 (246 reviews) | 
  | **Product Direction (% positive)** | 7.9 (45 reviews) | 8.5 (8 reviews) | 8.0 (278 reviews) | 

---
## Pricing

### Asterisk

#### Entry-Level Pricing

Plan: Metered SIP Trunking

Price: $0.02 per minute

Description: Works well for businesses that may need more flexibility in their communications week to week.

Key Features:
- No set-up fees.
- Metered inbound and outbound local and long distance.
- Allows more dynamic call volume activity.

[Browse all 2 editions](https://www.g2.com/products/asterisk/pricing)

#### Free Trial

Yes

### Twilio Elastic SIP Trunking

#### Entry-Level Pricing

No pricing available

#### Free Trial

No information available

### CallTower

#### Entry-Level Pricing

No pricing available

#### Free Trial

No information available

---
## Features Comparison By Category

### Contact Center

| Product | Score | Reviews |
|---|---|---|
| **Asterisk** | N/A | N/A |
| **Twilio Elastic SIP Trunking** | N/A | N/A |
| **CallTower** | 10.0/10 | 13 |

#### Channels

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Voice** | Not enough data | Not enough data | 9.4 (9 reviews) | 
| **Social** | Not enough data | Not enough data | Not enough data | 
| **Web Chat** | Not enough data | Not enough data | Not enough data | 
| **Mobile SMS** | Not enough data | Not enough data | Not enough data | 
| **Email** | Not enough data | Not enough data | Not enough data | 

#### Generative AI

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **AI Text-to-Speech** | Not enough data | Not enough data | Not enough data | 

#### Functions

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Session Routing** | Not enough data | Not enough data | 7.7 (5 reviews) | 
| **Session Queuing** | Not enough data | Not enough data | 9.0 (5 reviews) | 
| **Concurrent Calling** | Not enough data | Not enough data | 8.7 (5 reviews) | 
| **Speech Analytics** | Not enough data | Not enough data | Not enough data | 
| **Auto Dialer** | Not enough data | Not enough data | Not enough data | 
| **IVR** | Not enough data | Not enough data | Not enough data | 
| **Inbound Screen Pop** | Not enough data | Not enough data | Not enough data | 
| **Persistent Data** | Not enough data | Not enough data | Not enough data | 

#### Agentic AI - Contact Center

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Autonomous Task Execution** | Not enough data | Not enough data | Not enough data | 
| **Cross-system Integration** | Not enough data | Not enough data | Not enough data | 
| **Natural Language Interaction** | Not enough data | Not enough data | Not enough data | 
| **Proactive Assistance** | Not enough data | Not enough data | Not enough data | 

#### Administrative

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Session Summary Notes** | Not enough data | Not enough data | Not enough data | 
| **Administrator Access** | Not enough data | Not enough data | 9.0 (7 reviews) | 
| **Reporting & Dashboards** | Not enough data | Not enough data | 8.6 (6 reviews) | 
| **Session Recording** | Not enough data | Not enough data | Not enough data | 
| **Agent Scheduling and Assignment** | Not enough data | Not enough data | 9.3 (5 reviews) | 

### Call Center Infrastructure (CCI)

| Product | Score | Reviews |
|---|---|---|
| **Asterisk** | N/A | N/A |
| **Twilio Elastic SIP Trunking** | N/A | N/A |
| **CallTower** | 8.0/10 | 34 |

#### Platform

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Omnichannel** | Not enough data | Not enough data | 7.4 (25 reviews) | 
| **Mobile Access** | Not enough data | Not enough data | 7.7 (32 reviews) | 
| **Queue Management** | Not enough data | Not enough data | 8.0 (29 reviews) | 
| **Call Routing** | Not enough data | Not enough data | 8.4 (31 reviews) | 
| **Call Back** | Not enough data | Not enough data | 8.0 (28 reviews) | 
| **IVR** | Not enough data | Not enough data | 8.0 (27 reviews) | 
| **Automatic Call Distribution** | Not enough data | Not enough data | 8.5 (30 reviews) | 

#### Generative AI

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **AI Text-to-Speech** | Not enough data | Not enough data | 7.4 (24 reviews) | 

#### Workforce Management

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Call Monitoring** | Not enough data | Not enough data | 8.2 (30 reviews) | 
| **Performance Evaluation** | Not enough data | Not enough data | 8.1 (30 reviews) | 

#### Call Center Infrastructure (CCI)

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Autonomous Task Execution** | Not enough data | Not enough data | Not enough data | 
| **Cross-system Integration** | Not enough data | Not enough data | Not enough data | 
| **Natural Language Interaction** | Not enough data | Not enough data | Not enough data | 
| **Proactive Assistance** | Not enough data | Not enough data | Not enough data | 

#### Administrative

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Call Recording** | Not enough data | Not enough data | 8.0 (27 reviews) | 
| **Reporting & Dashboards** | Not enough data | Not enough data | 8.1 (27 reviews) | 

### VoIP Providers

| Product | Score | Reviews |
|---|---|---|
| **Asterisk** | 8.6/10 | 46 |
| **Twilio Elastic SIP Trunking** | N/A | N/A |
| **CallTower** | 7.5/10 | 177 |

#### Platform Basics - VoIP Providers

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **PBX systems, VoIP Softphone** | Not enough data | Not enough data | 8.5 (22 reviews) | 
| **Call Management** | Not enough data | Not enough data | 8.8 (23 reviews) | 
| **Network monitoring** | Not enough data | Not enough data | 6.8 (21 reviews) | 
| **Integrations** | Not enough data | Not enough data | 8.0 (25 reviews) | 
| **Virtual PBX** | Not enough data | Not enough data | 7.2 (21 reviews) | 
| **SIP trunking services** | Not enough data | Not enough data | 7.0 (22 reviews) | 

#### Basic Communication

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Phone Calls** | 9.5 (39 reviews) ✓ Verified | Not enough data | 9.0 (164 reviews) | 
| **Video Calls** | 8.1 (24 reviews) | Not enough data | 7.9 (130 reviews) | 
| **Instant Messaging** | 8.4 (23 reviews) ✓ Verified | Not enough data | 7.5 (125 reviews) | 
| **Screen Sharing** | 7.9 (21 reviews) | Not enough data | 7.9 (122 reviews) | 
| **Conference Calls** | 9.2 (34 reviews) ✓ Verified | Not enough data | 8.4 (143 reviews) | 
| **Desk-to-Desk Calls** | 9.0 (36 reviews) ✓ Verified | Not enough data | 8.7 (147 reviews) | 

#### Agentic AI - VoIP Providers

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Autonomous Task Execution** | Not enough data | Not enough data | 6.0 (12 reviews) | 
| **Cross-system Integration** | Not enough data | Not enough data | 6.0 (12 reviews) | 
| **Adaptive Learning** | Not enough data | Not enough data | 5.9 (11 reviews) | 
| **Proactive Assistance** | Not enough data | Not enough data | 5.8 (11 reviews) | 

#### Access

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Software Pairing** | 7.9 (25 reviews) | Not enough data | 7.9 (125 reviews) | 
| **Browser Extension** | 7.9 (23 reviews) ✓ Verified | Not enough data | 7.2 (114 reviews) | 
| **Individual Download** | 7.9 (24 reviews) | Not enough data | 7.4 (111 reviews) | 

#### Advanced Features

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Hold Music** | 9.1 (35 reviews) ✓ Verified | Not enough data | 7.4 (130 reviews) | 
| **Automated Attendants** | 9.0 (32 reviews) ✓ Verified | Not enough data | 7.9 (140 reviews) | 
| **VOiP Number** | 9.0 (33 reviews) ✓ Verified | Not enough data | 8.8 (144 reviews) | 

### Genesys AppFoundry Marketplace

| Product | Score | Reviews |
|---|---|---|
| **Asterisk** | N/A | N/A |
| **Twilio Elastic SIP Trunking** | N/A | N/A |
| **CallTower** | N/A | N/A |

#### Agentic AI - Genesys AppFoundry Marketplace

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Autonomous Task Execution** | Not enough data | Not enough data | Not enough data | 
| **Cross-system Integration** | Not enough data | Not enough data | Not enough data | 
| **Adaptive Learning** | Not enough data | Not enough data | Not enough data | 
| **Natural Language Interaction** | Not enough data | Not enough data | Not enough data | 
| **Proactive Assistance** | Not enough data | Not enough data | Not enough data | 
| **Decision Making** | Not enough data | Not enough data | Not enough data | 

### UCaaS Platforms

| Product | Score | Reviews |
|---|---|---|
| **Asterisk** | N/A | N/A |
| **Twilio Elastic SIP Trunking** | N/A | N/A |
| **CallTower** | 7.1/10 | 87 |

#### Agentic AI - UCaaS Platforms

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Autonomous Task Execution** | Not enough data | Not enough data | 5.9 (17 reviews) | 
| **Cross-system Integration** | Not enough data | Not enough data | 7.2 (23 reviews) | 
| **Adaptive Learning** | Not enough data | Not enough data | 5.9 (17 reviews) | 
| **Natural Language Interaction** | Not enough data | Not enough data | 5.7 (16 reviews) | 

#### Extensions

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Tenancy Flexibility** | Not enough data | Not enough data | 7.2 (65 reviews) | 
| **Native VoIP** | Not enough data | Not enough data | 8.0 (72 reviews) | 
| **CCaaS Option** | Not enough data | Not enough data | 7.4 (63 reviews) | 

#### Features

| Feature | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Voicemail to Email** | Not enough data | Not enough data | 8.3 (70 reviews) | 
| **Voicemail to SMS** | Not enough data | Not enough data | 6.9 (62 reviews) | 
| **File Sharing** | Not enough data | Not enough data | 6.7 (58 reviews) | 
| **Voice Conferencing** | Not enough data | Not enough data | 8.1 (67 reviews) | 
| **Video Conferencing** | Not enough data | Not enough data | 7.8 (63 reviews) | 
| **Conference Transcripts** | Not enough data | Not enough data | 7.0 (61 reviews) | 

---
## Categories
**Shared Categories (1):** [VoIP Providers](https://www.g2.com/categories/voip-providers)

**Unique to Asterisk (1):** [UCaaS Platforms](https://www.g2.com/categories/ucaas-platforms)

**Unique to Twilio Elastic SIP Trunking (1):** [Genesys AppFoundry Marketplace](https://www.g2.com/categories/genesys-appfoundry-marketplace)

**Unique to CallTower (3):** [UCaaS Platforms](https://www.g2.com/categories/ucaas-platforms), [Call Center Infrastructure (CCI) Software](https://www.g2.com/categories/call-center-infrastructure-cci), [Contact Center Software](https://www.g2.com/categories/contact-center)


---
## Reviewer Demographics

### By Company Size

| Segment | Asterisk | Twilio Elastic SIP Trunking | CallTower | 
|---|---|---|---|
| **Small-Business** | 30.8% | 50.0% | 24.9% | 
| **Mid-Market** | 50.0% | 50.0% | 63.6% | 
| **Enterprise** | 19.2% | 0% | 11.6% | 

### By Industry

#### Asterisk

- **Telecommunications:** 28.8%
- **Information Technology and Services:** 21.2%
- **Banking:** 5.8%
- **Computer Software:** 5.8%
- **Accounting:** 3.8%
- **Computer & Network Security:** 3.8%
- **Facilities Services:** 3.8%
- **Broadcast Media:** 1.9%
- **Computer Networking:** 1.9%
- **Consumer Goods:** 1.9%
- **Other:** 21.2%

#### Twilio Elastic SIP Trunking

- **Hospital & Health Care:** 20.0%
- **Oil & Energy:** 10.0%
- **Legal Services:** 10.0%
- **Insurance:** 10.0%
- **Information Technology and Services:** 10.0%
- **Health, Wellness and Fitness:** 10.0%
- **Construction:** 10.0%
- **Computer Software:** 10.0%
- **Computer & Network Security:** 10.0%

#### CallTower

- **Information Technology and Services:** 9.1%
- **Non-Profit Organization Management:** 6.6%
- **Manufacturing:** 6.3%
- **Financial Services:** 5.1%
- **Construction:** 4.0%
- **Hospital & Health Care:** 4.0%
- **Telecommunications:** 3.4%
- **Legal Services:** 2.9%
- **Retail:** 2.9%
- **Defense & Space:** 2.6%
- **Other:** 53.1%

---
## Alternatives

### Alternatives to Asterisk

- [Cisco Unified Communications Manager (CallManager)](https://www.g2.com/products/cisco-unified-communications-manager-callmanager/reviews) — 4.4/5 stars (111 reviews)
- [3CX](https://www.g2.com/products/3cx/reviews) — 4.4/5 stars (546 reviews)
- [RingEX](https://www.g2.com/products/ringex/reviews) — 4.2/5 stars (1364 reviews)
- [Zoom Workplace](https://www.g2.com/products/zoom-workplace/reviews) — 4.5/5 stars (56391 reviews)
- [Webex Calling](https://www.g2.com/products/webex-calling/reviews) — 4.5/5 stars (633 reviews)
- [GoTo Connect](https://www.g2.com/products/goto-connect/reviews) — 4.4/5 stars (1414 reviews)
- [Dialpad Connect](https://www.g2.com/products/dialpad-connect/reviews) — 4.4/5 stars (4165 reviews)
- [Yeastar S-Series VoIP PBX](https://www.g2.com/products/yeastar-s-series-voip-pbx/reviews) — 4.9/5 stars (15 reviews)
- [Linphone](https://www.g2.com/products/linphone/reviews) — 4.4/5 stars (16 reviews)
- [Twilio Flex](https://www.g2.com/products/twilio-twilio-flex/reviews) — 4.1/5 stars (36 reviews)

### Alternatives to Twilio Elastic SIP Trunking

- [Quo](https://www.g2.com/products/quo-quo/reviews) — 4.7/5 stars (3374 reviews)
- [Intermedia Unite](https://www.g2.com/products/intermedia-unite/reviews) — 4.5/5 stars (520 reviews)
- [Genesys Cloud CX](https://www.g2.com/products/genesys-cloud-cx/reviews) — 4.4/5 stars (1547 reviews)
- [CallHippo](https://www.g2.com/products/callhippo/reviews) — 4.5/5 stars (399 reviews)
- [Vonage Business Communications](https://www.g2.com/products/vonage-business-communications/reviews) — 4.3/5 stars (501 reviews)
- [Nextiva](https://www.g2.com/products/nextiva/reviews) — 4.5/5 stars (3566 reviews)
- [3CX](https://www.g2.com/products/3cx/reviews) — 4.4/5 stars (546 reviews)
- [Webex Calling](https://www.g2.com/products/webex-calling/reviews) — 4.5/5 stars (633 reviews)
- [Aircall](https://www.g2.com/products/aircall/reviews) — 4.4/5 stars (1585 reviews)
- [Telnyx CPaaS](https://www.g2.com/products/telnyx-cpaas/reviews) — 4.7/5 stars (525 reviews)

### Alternatives to CallTower

- [RingEX](https://www.g2.com/products/ringex/reviews) — 4.2/5 stars (1364 reviews)
- [Dialpad Connect](https://www.g2.com/products/dialpad-connect/reviews) — 4.4/5 stars (4165 reviews)
- [Nextiva](https://www.g2.com/products/nextiva/reviews) — 4.5/5 stars (3566 reviews)
- [GoTo Connect](https://www.g2.com/products/goto-connect/reviews) — 4.4/5 stars (1414 reviews)
- [Genesys Cloud CX](https://www.g2.com/products/genesys-cloud-cx/reviews) — 4.4/5 stars (1547 reviews)
- [Talkdesk](https://www.g2.com/products/talkdesk/reviews) — 4.4/5 stars (2504 reviews)
- [8x8 Work](https://www.g2.com/products/8x8-work/reviews) — 4.2/5 stars (926 reviews)
- [3CX](https://www.g2.com/products/3cx/reviews) — 4.4/5 stars (546 reviews)
- [Intermedia Unite](https://www.g2.com/products/intermedia-unite/reviews) — 4.5/5 stars (520 reviews)
- [Vonage Business Communications](https://www.g2.com/products/vonage-business-communications/reviews) — 4.3/5 stars (501 reviews)

---
## Top Discussions

### Asterisk

No discussions available for this product.

### Twilio Elastic SIP Trunking

- Title: [What does Twilio Elastic Sip Trunking do?](https://www.g2.com/discussions/what-does-twilio-elastic-sip-trunking-do) — 1 comment
  > **Top comment:** "Lets you connect your PBX phone system to the phone service."

### CallTower

- Title: [What is CallTower used for?](https://www.g2.com/discussions/what-is-calltower-used-for) — 1 comment
  > **Top comment:** "CallTower is a leading provider of cloud-based unified communications (UCaaS) and contact center solutions (CCaaS) that enhance business communication and..."

---
**Source:** [G2.com](https://www.g2.com) | [Comparison Page](https://www.g2.com/compare/asterisk-vs-twilio-elastic-sip-trunking-vs-calltower)