如何解码/编码电缆调制解调器配置文件？
我目前正在研究DOCSIS及相关的一些内部工作原理。我有点困惑的一件事是如何制作电缆调制解调器配置文件。
根据我收集到的信息：
- CM 配置是基于TLV格式的二进制文件。
- 这些配置使用 TFTP 服务器进行部署，并在调制解调器启动时通过 DHCP 提示给调制解调器本身。
I'm interested in knowing how these config files are structured. I have next to no knowledge of TLV aside from what I've read these past days.
- Is TLV just a generic method of stringing data together? It seems like TLV is used in both binary forms and json-like strings of clear text.
- Is the T and/or L parts of TLV a set size (in bytes)? How do I know where they separate?
- I think I read somewhere that CM configs use a subset of TLV called TLV-BER. If I'm not mistaken, this adds support for TLV nesting. How does this work?
I've heard that DOCSIS is well documented over at CableLabs, but I haven't been able to find this information yet. Helpful links are appreciated.
I have a binary config file in my possession that I've been able to decode using online tools, but assume I want to make my own tool for this purpose, how would I go about it?
Edit: Here's an excerpt of the first 64 bytes of the binary file, for reference.
03010112 01021916 08040668 51E00601 07070104 01020065 09040000 17C8181D
08040203 A0000904 00001F40 0E021F40 01020001 0F010207 01040601 07270101
03 01 01 ; 3 - Network access control: ON\n12 01 02 ; 18 - Max Number of CPEs: 2\n19 16 ; 25 - Downstream service flow\n 08 04 06 68 51 E0 ; 25.8 - Maximum Sustained Traffic Rate\n 06 01 07 ; 25.6 - Quality of Service Parameter Set Type: prov/adm/active\n 07 01 04 ; 25.7 - Traffic Priority: 4\n 01 02 00 65 ; 25.1 - Service Flow Reference or ASF Reference: 65\n 09 04 00 00 17 C8 ; 25.9 - Maximum Traffic Burst: 6,088\n18 1D ; 24 - Upstream service flow\n 08 04 02 03 A0 00 ; 24.8 - Maximum Sustained Traffic Rate: 33,792,000\n 09 04 00 00 1F 40 ; 24.9 - Maximum Traffic Burst: 8,000\n 0E 02 1F 40 ; 24.14 - Maximum Concatenated Burst: 8,000\n 01 02 00 01 ; 24.1 - Service Flow Reference or ASF Reference: 1\n 0F 01 02 ; 24.15 - Service Flow Scheduling Type: 2\n 07 01 04 ; 24.7 - Traffic Priority: 4\n 06 01 07 ; 24.6 - QOS: 0x07 (prov|adm|active)\n27 01 01 ; 39 - Enable 2.0 Mode: ON\n
类型
\n\nType Description Spec Defined\n======== ========================================================= ============\n0 Pad DOCSIS 1.0\n1 Downstream Frequency DOCSIS 1.0\n2 Upstream Channel ID DOCSIS 1.0\n3 Network Access Control Object DOCSIS 1.0\n4 DOCSIS 1.0 Class of Service DOCSIS 1.0\n5 Modem Capabilities Encoding DOCSIS 1.0\n6 CM Message Integrity Check (MIC) DOCSIS 1.0\n7 CMTS Message Integrity Check (MIC) DOCSIS 1.0\n8 Vendor ID Encoding DOCSIS 1.0\n9 SW Upgrade Filename DOCSIS 1.0\n10 SNMP Write Access Control DOCSIS 1.0\n11 SNMP MIB Object DOCSIS 1.0\n12 Modem IP Address DOCSIS 1.0\n13 Service(s) Not Available Response DOCSIS 1.0\n14 CPE Ethernet MAC Address DOCSIS 1.0\n15 Telephone Settings Option (deprecated) DOCSIS 1.0\n17 Baseline Privacy (Security) DOCSIS 1.0\n18 Max Number of CPEs DOCSIS 1.0\n19 TFTP Server Timestamp DOCSIS 1.0\n20 TFTP Server Provisioned Modem IPv4 Address DOCSIS 1.0\n21 SW Upgrade IPv4 TFTP Server DOCSIS 1.0\n22 Upstream Packet Classification DOCSIS 1.1\n23 Downstream Packet Classification DOCSIS 1.1\n24 Upstream SF DOCSIS 1.1\n25 Downstream SF (11.4) DOCSIS 1.1\n26 Payload Header Suppression DOCSIS 1.1\n27 HMAC-Digest DOCSIS 3.1\n28 Maximum Number of Classifiers DOCSIS 1.1\n29 Privacy Enable DOCSIS 1.1\n30 Authorization Block DOCSIS 1.1\n31 Key Sequence Number DOCSIS 1.1\n32 Manufacturer Code Verification Certificate DOCSIS 1.1\n33 Co-Signer Code Verification Certificate DOCSIS 1.1\n34 SNMPv3 Kickstart Value DOCSIS 1.1\n35 Subscriber Mgmt Control DOCSIS 1.1\n36 Subscriber Mgmt CPE IPv4 List DOCSIS 1.1\n37 Subscriber Mgmt Filter Groups DOCSIS 1.1\n38 SNMPv3 Notification Receiver DOCSIS 1.1\n39 Enable 2.0 Mode DOCSIS 2.0\n40 Enable Test Modes DOCSIS 2.0\n41 Downstream Channel List DOCSIS 2.0\n42 Static Multicast MAC Address DOCSIS 2.0\n43 DOCSIS Extension Field DOCSIS 1.0\n44 Vendor Specific Capabilities DOCSIS 1.0\n45 Downstream Unencrypted Traffic (DUT) Filtering DOCSIS 2.0\n46 Transmit Channel Configuration (TCC) DOCSIS 3.0\n47 Service Flow SID Cluster Assignment DOCSIS 3.0\n48 Receive Channel Profile DOCSIS 3.0\n49 Receive Channel Configuration DOCSIS 3.0\n50 DSID Encodings DOCSIS 3.0\n51 Security Association Encoding DOCSIS 3.0\n52 Initializing Channel Timeout DOCSIS 3.0\n53 SNMPv1v2c Coexistence DOCSIS 3.0\n54 SNMPv3 Access View Configuration DOCSIS 3.0\n55 SNMP CPE Access Control DOCSIS 3.0\n56 Channel Assignment Configuration Settings DOCSIS 3.0\n57 CM Initialization Reason DOCSIS 3.0\n58 SW Upgrade IPv6 TFTP Server DOCSIS 3.0\n59 TFTP Server Provisioned Modem IPv6 Address DOCSIS 3.0\n60 Upstream Drop Packet Classification DOCSIS 3.0\n61 Subscriber Mgmt CPE IPv6 Prefix List DOCSIS 3.0\n62 Upstream Drop Classifier Group ID DOCSIS 3.0\n63 Subscriber Mgmt Control Max CPE IPv6 Prefix DOCSIS 3.0\n64 CMTS Static Multicast Session Encoding DOCSIS 3.0\n65 L2VPN MAC Aging Encoding DOCSIS 2.0\n66 Management Event Control Encoding DOCSIS 3.0\n67 Subscriber Mgmt CPE IPv6 Prefix List DOCSIS 3.0\n68 Default Upstream Target Buffer Configuration DOCSIS 3.0\n69 MAC Address Learning Control Encoding DOCSIS 3.0\n70 Upstream Aggregate Service Flow Encodings DPoE 2.0\n71 Downstream Aggregate Service Flow Encodings DPoE 2.0\n72 Metro Ethernet Service Profile DPoE 2.0\n73 Network Timing Profile DPoE 2.0\n74 Energy Management Parameter Encoding DOCSIS 3.0\n75 Energy Mgt. Mode Indicator DOCSIS 3.1\n76 Energy Mgt. Identifier List for CM DOCSIS 3.1\n77 DOCSIS Time Protocol Enable DOCSIS 3.1\n78 AQM Disable DOCSIS 3.1\n79 UNI Control Encoding DOCSIS 3.0\n80 Energy Management \xe2\x80\x93 DOCSIS Light Sleep Encodings DOCSIS 3.1\n81 Manufacturer CVC Chain DOCSIS 3.1\n82 Co-signer CVC Chain DOCSIS 3.1\n83 L2CP Management DPoE 2.0\n201-231 eCM eSAFE Configuration File TLVs\n201 ePS\n202 eRouter eRouter\n203-215 Reserved\n216 eMTA PacketCable 1.x\n217 eSTB DSG\n218 Reserved\n219 eTEA TEI\n220 eDVA PacketCable 2.0\n221 eSG SMA gateway\n222-231 Reserved\n255 End-of-Data DOCSIS 1.0\n