Description: The value of tmnxOamPingCtlSize specifies the size of the OAM Echo message.

When tmnxOamPingCtlTestMode has a value of 'mtuPing', changing the message size is a method of checking the ability of an SDP to support a particular path-mtu value. The size of the message does not include the SDP encapsulation, VC-Lable (if applied) or any DLC headers or trailers.

When the OAM message is encapsulated in an IP/GRE SDP, the IP 'DF' (Don't Fragment) bit is set. If any segment of the path between the sender and receiver cannot handle the message size, the message is discarded. MPLS LSPs are not expected to fragment the message either, as the message contained in the LSP is not an IP packet.

In the case of 'lspPing' the minimum size allowed is 84 octets. In the case of 'vccvPing' the minimum size allowed is 88 octets. In the case of 'sdpPing' the minimum size allowed is 72 octets. Before 6.0 release, the minimum size in 'sdpPing' is 40 octets. Such shorter packet has no timestamp information but should still be accepted for interoperability purpose. However, new 'sdpPing' should include the timestamp information. In the case of 'icmpPing' the minimum size allowed is 0 octet. In the case of 'macPing', 'mfibPing' and 'vprnPing' the minimum size allowed is 1 octet.

In the case of all the test types except 'icmpPing' the maximum size allowed is 9198 octets. In the case of 'icmpPing' the maximum size allowed is 16384 octets.

When tmnxOamPingCtlTestMode has a value of 'icmpPing', the value of this object specifies the payload size following the ICMP header. The default size for 'icmpPing' is 56 octets.

This parameter is optional and is valid only if tmnxOamPingCtlTestMode has a value of either 'sdpPing' ,'mtuPing', 'macPing', 'lspPing', 'vprnPing', 'mfibPing', 'vccvPing' or 'icmpPing'.