What Are Dial Peers in Cisco Voice? (Simple Guide for Beginners)
Dial peers are the fundamental building blocks of call routing in Cisco voice networks. Think of dial peers as digital phone routes that tell Cisco routers or gateways where to send a phone call. In other words, without dial peers, calls cannot be placed or routed in Cisco VoIP systems.
Why Dial Peers Matter
Dial peers define the calling path. They decide whether a call is internal, external, VoIP, or to a PSTN phone.
Types of Dial Peers
1. POTS Dial Peers
Used for connecting to PSTN or analog phones.
2. VoIP Dial Peers
Used for VoIP calls such as:
- CUCM to Gateway
- Gateway to Gateway
- SIP trunking
Dial Peer Matching
When a user dials a number, the router compares the digits and selects the matching dial peer.
Dial Peer Parameters
- Destination pattern (phone number to match)
- Session target (where to send call)
- Codec
- DTMF relay
- VoIP protocol (SIP/H.323/MGCP)
Example VoIP Dial Peer
dial-peer voice 100 voip destination-pattern 9T session target ipv4:10.1.1.10 codec g711ulaw dtmf-relay rtp-nte
POTS Dial Peer Example
dial-peer voice 200 pots destination-pattern 555.... port 0/0/0
Dial Peer Best Practices
- Use descriptive dial peer numbers
- Prefer exact patterns over wildcards
- Test call routing using debug commands
Conclusion
Dial peers are the call routing brains of Cisco voice networks. Master them, and you master Cisco telephony!