Mar 10

Cisco SRV Records – Quick Reference SRV 0 1 8443 (Presence Publisher/Subscriber) SRV 0 1 8443 (Publisher/Subscriber) SRV 0 0 69 (TFTP) SRV 0 0 80 (CCMCMIP) SRV 0 0 5060 (VCS Control – Internal) SRV 0 0 5060 (VCS Expressway – External) SRV 0 0 443 (Free Jabber Video) SRV 0 0 8443 (Expressway-E)

Dec 16

CUCM and IM&P Integration with SRV Records

For us Cisco techs, one of the more often than not nowadays is that have to deal with the MS world of DNS (AND Certifciate Architecture… I’ll talk about this in later articles). I’ve had a fair bit of experience with DNS in the past, so I thought I would just share a little about integrating CUCM with IM & Presence using SRV records both ways to support CUCM Clusters and IM & Presence Clusters for high availability.

DNS Configuration

Create A (Host) Records

CUCM DNS A Records

Type Hostname IP Address

IM&P DNS A Records

Type Hostname IP Address

Create SRV Records

IM&P Cluster Name:

Type Identifer Protocol Weight Priority Host
SRV _sip _tcp 10 10
SRV _sip _tcp 10 10

CUCM Cluster Name:

Type Identifer Protocol Weight Priority Host
SRV _sip _udp 10 10
SRV _sip _udp 10 10

Verify Records via NSLOOKUP

>  set q-all

The above should output the following results.

-        The SRV Records and their target hosts
-        An A record for every target host identified in the SRV record.

CUCM Configuration

SIP Trunk

  1. Navigate to Device, then select Trunks
  2. Select Add New
  3. Select SIP Trunk for Trunk Type
  4. Select Next
  5. Complete the details of the SIP Trunk as per normal.
  6. Under SIP Information, check the box  Destination Address is SRV

Note: When the checkbox is ticked, CUCM changes the outbound SIP protocol from udp to tcp.

  1. Type the IM&Presence Cluster Name. (
  2. Select Save and then reset the Trunk.

Configure SIP Publish Trunk

  1. Navigate to the Service Parameters, then Cisco CallManager.
  2. Find “IM & Presence Publish Trunk”
  3. Drop the arrow down and select the above SIP Trunk.

 IM & Presence Configuration

SRV Cluster Name

  1. Navigate to Service Parameters, then Cisco SIP Proxy.
  2. Find “SRV Cluster Name”
  3. Type the IM&Presence cluster name (
  4. Select Save

Presence Gateway

  1. Navigate to Presence, then Gateways.
  2. Select Add New
  3. Select CUCM for Presence Gateway Type.
  4. Type a Descriptive note.
  5. Type the SRV Record for the CUCM Cluster Name.

Note: Do not strip the SRV Identifier or Protocol. Example input would be