12-02-2009 08:32 AM - edited 03-12-2019 09:24 AM
Cisco UCM version 7.0 and Cisco UCME 8.0 (IOS 15.0(1)XA) introduce version 17 of the SCCP signaling protocol. SCCPv17 significantly changes message formats from previous versions. User functionality will be impacted if a network device that lacks SCCPv17 support attempts NAT fixup or inspection of the SCCP protocol.
Symptoms are more likely to be observed with:
Various symptoms may be observed based on devices, versions and topology. Some symptoms may include:
SCCP Protocol version can be identified in the SCCP StationRegister message. Most significant bytes indicate feature support and least significant bytes indicate protocol version. Here is an example of SCCPv17 StationRegister message from a 7970 model phone running 8.4 phone load registering to UCM7.0(1). Decimal 17 = Hex 0x11:
Recommendations for complete Cisco solution are covered in Cisco Unified Communications System Documentation. Specifically Cisco UCM 7.0 is covered by the System Release Notes for IP Telephony: Cisco Unified Communications System, Release 7.0(1) . Information below supplements the System Release Notes.
ASA and PIX support for SCCPv17 was added via CSCso36036 This fix is included in versions 8.0.3.22, 8.1.2, and 8.2.1 - and later.
Additionally, please be aware of the following defect which may trigger a crash when SCCPv17 messages are processed by the security appliance: CSCsz06748 This bug is resolved in the following versions: 8.0.4.33, 8.1.2.24, and 8.2.1.2
FWSM support for SCCPv17 was added via CSCso38805 This fix is included in version 4.0.3 and later.
Support for SCCPv17 was added to IOS Zone-Based Firewall via
CSCso53203 Support IOS FW interopreability with CUCM 7.0 running SCCP v17
starting with versions 12.4(20)T1. Legacy IOS Firewall (CBAC) will not support SCCPv17
Support for SCCPv17 in IOS NAT is not currently available, but is being considered with:
Please monitor CSCsy93500 for updates on IOS NAT support of SCCPv17.
SCCP phones initiate version negotiation. It is possible to downgrade phones to use and older version of SCCP. Downgrading phones will cause some loss of functionality. Older phone loads are not extensively tested with newer CM versions so long term production deployment is not recommended. See the Cisco Unified Communications Compatibility Tool for recommended versions.
Phones using older SCCP versions may be peripherally affected when:
Questions? E-Mail Wes Sisk
Is there any workaround for CIPC?
Recent versions of CIPC can use SIP. Switching to SIP is a viable workaround. SIP has near feature parity with SCCP now:
CIPC contacts tell me the current version of CIPC is based on the 8.3(5) phone load. That phone load does uses an earlier version of SCCP so it should not be subject to this problem.
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