3 SCAP Compliance

This chapter explains the summary of changes that affect DCD to make it SCAP compliant.

SCAP

Ericsson SCAP is a vendor specific protocol that utilizes the Draft version 8 of the Diameter Base Protocol (the predecessor to RFC 3588).

The Convergent Charging Controller Diameter protocol is based upon the final version of RFC 3588. The base protocol is further extended to support the use of CCR (Credit-Control-Request) / CCA (Credit-Control-Answer) messages, described by RFC 4006.

SCAP, on the other hand, adds Attribute Value Pair (AVP)s to Diameter base protocol’s Accounting-Request (ACR) and Accounting-Answer (ACA) commands.

DCD may be reconfigured to permit it to interact with an Ericsson SCAP compliant server as a SCAP client. Variances between the SCAP and normal Credit-Control charging approaches available within DCD are described below.

Note:

The necessary changes will take effect only if the enableDraft8 is set to true.

Application-Identifiers Values

This table lists the different Application-identifier values between the Diameter Base Protocol Draft 8 and RFC 3588 final version.

Table 3-1 Comparison of Application-Identifier Values in Diameter Base Protocol Draft 8 and RFC 3588

Draft 8 Final
- Diameter Common Messages 0
NASREQ 1 NASREQ 1
CMS Security 2 Mobile-IP 2
Mobile IP 4 -
Relay 0xffffffff Relay 0xffffffff

Message Header

This table describes the changes to message header values.

Table 3-2 Message Header Values

Section Heading Comment
Vendor-Id

This should be changed in outbound messages (at the Oracle Diameter stack level).

See Vendor-Id for SCAP specific changes.

T-flag

The T-flag (retransmit) is used by a Diameter client to indicate to the server that a message has been retransmitted (possibly due to loss of message).

This flag is not supported by Draft 8, and hence it is not set while retransmitting duplicate DCD messages to SCAP.

Supported AVPs

This table describes the changes to the supported AVPs to enable SCAP compliance.

Table 3-3 Supported AVPs

Supported AVP Comment
Event-Timestamp DCD to send vendor specific version for Ericsson SCAP.
Inband-Security-Id This AVP is not sent during capabilities exchange, if SCAP support is configured, that is, when enableDraft8 is set to true.

Result-Codes

This table describes the changes to the Result-Codes to enable SCAP compliance.

Table 3-4 Result Code Changes for SCAP Compliance

Result Code [DRAFT8] Value [3588] Value
DIAMETER_UNSUPPORTED_TRANSFORM 5010 -
DIAMETER_NO_COMMON_APPLICATION 5011 5010
DIAMETER_UNSUPPORT_VERSION 5012 5011
DIAMETER_UNABLE_TO_COMPLY 5013 5012
INVALID_BIT_IN_HEADER 5014 5013
INVALID_AVP_LENGTH 5015 5014
INVALID_MESSAGE_LENGTH 5016 5015
INVALID_AVP_BIT_COMBO 5017 5016
DIAMETER_NO_COMMON_SECURITY - 5017