Dell Force10 E300, Configuration Manual

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1008 | SONET/SDH
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• Protection switching is not supported.
• POS interfaces cannot be mirrored ports.
• Configurable alarm thresholds (SF/SD BER, B1/B 2/B3 TC) are not supported.
• The CRC type and S1S0 flag cannot be changed.
Configuring POS Interfaces
POS interfaces require several configuration considerations, including
• Encapsulation
• MTU
• Clock Settings
Encapsulation
The E-Series’ POS line card requires PPP encapsulation. A SONET interface without encapsulation is
always administratively down.
Packet Over SONET interfaces require several configuration considerations.
When enabling encapsulation on an interface, PPP negotiation only begins after it has been turned on using
the
no shutdown
command. You can enable authentication and other related commands after negotiation is
completed. When removing encapsulation using the
no encap
command on a SONET interface, the
interface is administratively shutdown and all configuration information (IP addresses for example) is
deleted from the interface.
Equipment vendors use unique defaults for PPP encapsulation. When configuring PPP encapsulation
between the E-Series and another vendor’s equipment, verify the following settings:
• One side of the link is set using the command
clock source internal
.
• Default SONET settings are compatible. The E-Series defaults to ATM scrambling disabled; flag is C2
0xCF(207), J0 is 0xCF(207).
• A common PPP authentication method is configured. FTOS supports Challenge-Handshake
Authentication Protocol (CHAP) and/or Password Authentication Protocol (PAP) authentication.
• The MTU and IP MTU settings on both ends of the link are the same. If you input the
ip mtu
command
with a value which differs from the far-end interface, the interface on the E-Series will go down.
• Confirm that the MTU settings are the same on both end of the link. If you configure the
ip mtu
command with a different value on the far end of the link, the interface on the E-Series goes down.
Note: SONET uses synchronous transport signal (STS) framing. When framing is configured
on an interface, it should only be done when the interface is shut down.